Date logic generator

Abstract

A utility with which a programmer can generate or alter computer code for a calendaring function, and test the code prior to compilation. Entering the program in edit mode, the programmer locates a portion of the program where code for a calendaring function is to be generated or altered, and invokes the date logic generator. The date logic generator provides an initial window with a choice of calendaring functions, and upon selecting a calendaring function, a parameters window displaying a number of first-level parameters for that function is provided. Depending on the specification of the values of the first-level parameters, sub-windows with second-level parameters may be provided. And, in general, depending on the specification of the values of the n-level parameters, (n+1)-level parameters may be provided in sub-windows. The parameters provided at any instant are only those which have already been specified or those that require specification. When the programmer believes the calendaring function is correctly chosen and its parameter values correctly specified, the operation of the function may be tested by a testing utility without requiring compilation of the computer code. Data for the calendaring function is entered in a testing utility sub-window, and the programmer can compare the testing utility output with an expected output. If the testing utility output and the expected output differ the programmer can modify the function or the function parameter values as appropriate. Further runs of the testing utility and modifications of the parameters of the calendaring function can be performed as needed.

Claims

What is claimed is:

1. A utility for generating computer code for a calendaring function at a selected location in a computer program edited on a computer system, comprising:

means for presenting a choice of calendaring functions on a display screen of said computer system;

means for selecting said calendaring function from said choice of calendaring functions;

means for presenting a choice of first-level parameter values associated with said calendaring function wherein said first-level parameter values possibly includes both terminal parameter values and non-terminal parameter values;

means for selecting a first-level parameter value from said choice of first-level parameter values;

means for generating said computer code for said calendaring function with said first-level parameter value at said selected location in said computer program;

means for presenting a choice of second-level parameter values if said first-level parameter value is one of said non-terminal parameters; and

means for selecting a second-level parameter value from said choice of second-level parameter values if said first-level parameter value is one of said non-terminal parameter values, and wherein said means for generating generates computer code for said calendaring function with said second-level parameter value, if said first-level parameter value is one of said non-terminal parameter values.

2. A utility for generating computer code for a calendaring function at a selected location in a computer program edited on a computer system, comprising:

means for presenting a choice of calendaring functions on a display screen of said computer system;

means for selecting said calendaring function from said choice of calendaring functions;

means for presenting a choice of first-level parameter values associated with said calendaring function;

means for selecting a first-level parameter value from said choice of first-level parameter values;

means for generating said computer code for said calendaring function with said first-level parameter value at said selected location in said computer program;

means for providing a test value for said first-level parameter value of said calendaring function; and

means for obtaining an output, prior to compilation of said computer code, from said calendaring function with said first-level parameter value equal to said test value.

3. The utility of claim 2 further including:

means for making a second selection of a second calendaring function from said choice of calendaring functions;

means for specifying a second value for a second first-level parameter value associated with said second calendaring function; and

means for generating modified computer code for said second calendaring function with said second first-level parameter value at said selected location in said computer program.

Description

BACKGROUND OF THE INVENTION

The present invention is directed to a system for assisting a date logic programmer in the generation of date logic, and also to such a system where the generated date logic can be subjected to a series of tests so that the date logic programmer can confirm that correct and appropriate date logic has been generated.

Traditionally, date logic code for a calendaring program is written by a programmer "by hand," and therefore must be thoroughly tested to insure that the date logic code functions as intended. In some cases, the programmer will have written similar or equivalent code, or will have access to similar or equivalent code, which can be copied to the appropriate location in the calendaring program. Even if the copied code is at first inspection equivalent to the code required, the input and output parameters must be altered so as to interface correctly given the new location of the code. Although this somewhat reduces the likelihood of programming errors, it by no means eliminates the chance that the date logic code will not function correctly, since the date logic may not be equivalent or as similar as thought, or may not interface as thought with the environment provided by the surrounding program. Therefore, the code must still be tested thoroughly to insure that it functions as intended.

To test the calendaring function the programmer must first compile the new code, then run the code, and then compare the output from the code with the output expected in view of data values supplied by the data files or internally generated by the program. This is time consuming and inconvenient for a number of reasons: the program must be recompiled after every alteration of the code; the values in the data files may produce output values from the calendaring function which will not be easy to verify as correct; or internally-generated data values may produce output values from the calendaring function which will not be easy to verify as correct. Alteration of the internally-generated data values is therefore generally extremely inconvenient.

The date logic generator of the present invention provides a calendaring utility which generates calendaring functions, and allows the programmer to test the calendaring functions in a straightforward manner without recompilation of the code. To use the date logic generator, a programmer enters a program in edit mode, locates a portion of the program where the computer code for a calendaring function is to be altered or new code is to be generated, and calls the date logic generator. The date logic generator provides an initial window with a choice of calendaring functions. Upon selecting a calendaring function, a parameters window for that function is provided. A number of first-level parameters titles are initially displayed in the parameters window, and if those parameters have default values, the default are also displayed. Depending on the specification by the programmer of the values of the first-level parameters, sub-windows with second-level parameters titles may be provided for specification, and if parameters have default values, then the default are also displayed. In general, depending on the specification by the programmer of the values of the n-level parameters, (n+1)-level parameters titles may be provided in sub-windows for specification. The displayed parameters titles provided at any time are only those whose values have been specified or whose values require specification, thereby making the utility simple to use.

When the programmer believes the calendaring function has been correctly specified, the operation of the function may be tested by the date logic generator of the present invention, without requiring recompilation of the computer code. To test the calendaring function the programmer invokes the testing utility, provides data for the calendaring function in a testing sub-window providing by the testing utility, and runs the testing utility. The programmer can then compare the output of the testing utility with an expected output and, if the output does not correspond to the output expected from the desired calendaring function, modify the values of the parameters of the calendaring function as appropriate. Further runs of the testing utility and modifications of the parameters of the calendaring function can be performed as needed.

By providing parameter windows where all but the required parameter titles are hidden, by allowing the testing of the calendaring functions with data provided by the programmer while in the utility, and by generating the computer code based on the specified parameters values, the date logic generator of the present invention is extremely advantageous. With the date logic generator of the present invention, calendaring code is generated more quickly, efficiently and accurately than previously possible.

The calendaring utility of the present invention includes a variety of calendaring functions, features and options which have been selected to provide a calendaring system which should perform most any required purpose. The many functions, features and options of the present invention are useful per se, and in combination provide a synergistic advantage by virtue of their completeness, so a programmer will not need to augment the calendaring functions provided.

The calendaring utility of the present invention allows the programmer to choose among at least ten different holiday tables. This can be useful if the programmer conducts business with outside areas of commerce, such as foreign commerce, or if various areas of the programmer's shop observe different holiday schedules.

The calendaring utility also allows the programmer to specify dates at least fifty-two different date formats. The utility also permits the programmer to define each day of the week as a processing day or a nonprocessing day. When processing and nonprocessing days are defined, holidays may be taken into consideration. The utility also allows the programmer to select any of the twelve months as the start of the fiscal year, and permits the programmer to specify day 01 through 28 as the start of the fiscal month. Additionally, the utility allows the programmer to specify whether the "from-date" and/or the "to-date" should be counted in calendaring calculations. The utility also provides implicit and explicit access to the current date.

The utility offers the programmer over three hundred functions. These functions fall into three basic groups: utility functions, calendar day functions, and processing day functions. Calendar day functions perform date calculations based on calendar days, and processing day functions perform date calculations based on processing days. Utility functions perform date calculations which are independent of calendar day and/or processing day considerations. Functions provided by the system allow for date calculations based on calendar or fiscal time units (i.e., years, months or quarters).

It should be noted that the year 2000 is rapidly approaching and there are a number of reasons why the upcoming century transition, from 1999 to 2000, poses problems to many currently existing calendaring systems. First, data processing systems that examine only the last two digits of the year may conclude, for instance, that the year 2000 is earlier than the year 1999, simply because 00 is less than 99. This is known as "inversion of years." Second, although the year 2000 is a leap year, data processing systems that have incomplete leap-year logic may not be aware that (although the years 1900 and 2100 are not leap years) the year 2000 is a leap year. Third, since the year 2000 ends in the digits `00`, data processing systems that divide by the two-digit representation of the year run the risk of terminating abnormally. The calendaring functions of the present invention address these, and other calendar-related problems. The utility of the present invention can handle any four digit year, i.e., any year from 0001 through 9999. The system uses a set of rules which distinguishes all leap years from nonleap years in this range.

Among the functions provided by the utility of the present invention are conversions between a 360-day-year calendar and the Gregorian and Julian calendars. Gregorian dates are based on the Gregorian calendar where, according to the old rhyme, "Thirty days hast September, April, June and November; All the rest have thirty-one; Except for February which has 28 days clear; And 29 in each leap year." A Julian date has a year and a day-of-the-year between 1 and 365. For example, since January has 31 days, the Gregorian date of Feb. 5, 1995 is written in Julian form as 036/1995. Method and apparatus for conversion between Julian and Gregorian calendars are well-known in the art, and any efficient system can be used in conjunction with the calendar conversions of the utility of the present invention.

The 360-day-year calendar was developed for financial calculations because of the simplicity of a year where each month has 30 days. For instance, the day-of-the-year which is 46% of a year past March 1 is easily determined by noting that 169.2 is 46% of 360, and since it is easily determined that 169 equals 5.times.30 plus 19, an increment of 169 days in a 360-day-year is an increment of five months and nineteen days. Therefore, August 20 is 46% of a year past March 1 according to a 360-day-year calculation. Another advantage of the use of a 360-day year calendar is that many fractional year increments are equal to an integer number of months: one twelfth of a year is one month, one sixth of a year is two months, one fourth of a year is three months, one third of a year is four months, and one half of a year is sixth months. Although this type of simplification is not of as much use in the current age of microelectronics, many financial institutions still use 360-day-year methods for ongoing calculations which were started using a 360-day-year method. Also, 360-day-year methods are implemented in business or legal situations where such methods remain a standard.

Typically, conversion of Gregorian or Julian dates to 360-day-year dates and conversion of 360-day-year dates to Julian or Gregorian dates is accomplished using algebraic methods. However, such algebraic methods generate dates which do not actually exist, or generates gaps between existing dates. In contrast, the utility of present invention converts Gregorian calendar dates to dates of a 360-day-year calendar, and 360-day-year calendar dates to Gregorian calendar dates, using a single three-column 367-entry conversion table. A search table unit searches the conversion table from the bottom upwards, i.e., a table search index is initialized to a value of 367, and decremented by unity each time a comparison is made and a match is not found, thereby insuring that all Gregorian and Julian dates generated do exist

An object of the present invention is therefore to provide a utility for assisting a date logic programmer in the generation of date logic.

Another object of the present invention is to provide a utility which reduces the likelihood of errors in the generation of date logic.

Another object of the present invention is to provide a utility for increasing the reliability of date logic code.

Another object of the present invention is to provide a straightforward and nontechnical utility for the generation of date logic.

Another object of the present invention it to provide a utility for the generation of date logic which displays only those parameter sub-windows which are relevant in view of the parameter values which have already been specified.

Another object of the present invention is provide a utility where date logic can be subjected to one or more real-time tests so that the programmer can confirm that correct and appropriate date logic has been generated.

Another object of the present invention is provide a utility with which a programmer can generate and test date logic source code without requiring the compilation of the code.

Another object of the present invention is provide a utility where a selected calendaring function or its parameters can be easily altered, particularly if tests indicate that an incorrect calendaring function or function parameters were previously specified.

Further objects and advantages of the present invention will become apparent from a consideration of the drawings and the ensuing detailed description.

The present invention is directed to a utility which generates computer code for a calendaring function at a selected location in a computer program. The utility includes a means for presenting a choice of calendaring functions on the computer display screen, a means for selecting the calendaring function from amongst the choice of calendaring functions, a means for presenting a choice of parameters associated with the calendaring function, a means for specifying values for the parameters, and a means for generating the computer code for the calendaring function with the specified parameter values at the selected location in the computer program.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, schematically illustrate a preferred embodiment of the invention and, together with the general description of the preferred embodiment given below, serve to explain the principles of the invention.

FIG. 1a is a schematic representation of a computer system utilizing the calendaring system of the present invention.

FIG. 1b is a schematic representation of an alternate computer system utilizing the calendaring system of the present invention.

FIG. 2 is a diagram of interactions between the calling program and the calendaring program of the present invention.

FIG. 3 is a list of input and output parameters for the calendaring system of the present invention.

FIG. 4a is a flow chart for the method for determination of leap years according to the present invention.

FIG. 4b is a flow chart for the method of calculation of the absolute days corresponding to a given date according to the method of determination of leap years shown in FIG. 4a.

FIG. 5a is a diagram illustrating entry of holiday tables to the system of the present invention.

FIG. 5b is a table showing which reports and listings are generated when the input is good, bad, or nonexistent.

FIG. 5c is a flow chart for a method of counting days between a FROM-DATE and a TO-DATE, incorporating features such as changeable endpoints and processing day definitions, according to the present invention.

FIG. 5d is a flow chart for a method of determining a TO-DATE a specified number of days from a FROM-DATE, incorporating features such as changeable endpoints and processing day definitions, according to the present invention.

FIGS. 6-14, 15a-b, 16a-b, 17-23, 24a-d, 25a-b, 26a-b, 27a-b and 28a-b show examples of function calls according to the methods of the present invention.

FIG. 29A shows an apparatus for conversion from a Gregorian day-of-the-year to a 360-day-year day-of-the-year.

FIG. 29B shows an apparatus for conversion from a 360-day-year day-of-the-year to a Gregorian day-of-the-year.

FIG. 29C shows a flow chart for the Search Table unit of FIG. 29A.

FIG. 29D shows a flow chart for the Search Table unit of FIG. 29B.

FIGS. 30A-30H provide COBOL computer code for the calendar conversion table of the present invention.

FIG. 31 provides a graphical representation of date conversion entries of the table of FIG. 30 for a leap year.

FIG. 32 provides a graphical representation of date conversion entries of the table of FIG. 30 for a non-leap year.

FIG. 33 shows a flowchart for the selection of a calendaring function, the specification of the parameter values, testing of the function, and generation of the source code.

FIG. 34 shows a flowchart for the specification of the values of parameters from a plurality of levels.

FIG. 35 shows the primary option menu screen.

FIG. 36 shows the function selection screen.

FIG. 37 shows a parameter specification screen for a NEXT DAY function.

FIG. 38 shows another parameter specification screen for a NEXT DAY function with a sub-window displayed for second-level parameters.

FIG. 39 shows another parameter specification screen for a NEXT DAY function.

FIG. 40 shows a parameter specification screen for a DAYS SINCE/UNTIL function.

FIG. 41 shows the code generated by the date logic generator for the DAYS SINCE/UNTIL function with parameter values as shown in FIG. 40.

FIG. 42 shows a parameter specification screen for a REFORMAT DATE function with the testing sub-window displayed.

FIG. 43 shows a parameter specification screen for a REFORMAT DATE function with a test input entered in the testing sub-window.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will be described in terms of a preferred embodiment. The preferred embodiment is a date logic generator with which a programmer can specify a calendaring function and the values of its parameters, test the calendaring function to insure it operates as expected, and generate the computer code for the calendaring function with the specified parameter values. The present specification includes a first section where the 365-day-year calendaring functions of the present invention are described, a second section where the 360-day-year calendaring functions of the present invention are described, and a third section where the date logic generator of the present invention is described.

365-Day-Year Calendaring Functions

The year 2000 is rapidly approaching and there are a number of reasons why the upcoming century transition, 1999 to 2000, poses problems to data processing calendaring systems. First, data processing systems that examine only the last two digits of the year may conclude, for instance, that the year 2000 is earlier than the year 1999, simply because 00 is less than 99. This is known as "inversion of years." Second, although the year 2000 is a leap year, data processing systems that have incomplete leap-year sensitive logic may not be aware that the year 2000 is a leap year, though the years 1900 and 2100 are not. Third, since the year 2000 ends in the digits `00`, data processing systems that divide by the two-digit representation of the year run the risk of terminating abnormally.

The calendaring system of the present invention addresses these, and other calendar-related problems. The system can handle any four digit year, i.e., any year from 0001 through 9999. The system uses a set of rules which distinguishes all leap years from nonleap years in this range.

Leap-year rules were initiated in 46 B.C. by Julius Caesar, and modified in 1582 by Pope Gregory XIII. In the Julian calendar a leap year of 366 days occurs once every four years. Over the course of sixteen centuries this approach produced eleven days of error. In the leap year rules instituted by Pope Gregory XIII, a calendar year that is a multiple of 100 is not a leap year unless it is also a multiple of 400. The resulting Gregorian calendar represents a significant improvement over the Julian calendar and yields only about three days of error every 10,000 years.

The calendaring system of the present invention spans 10,000 years and so it is necessary to enhance the leap year rules further still. The leap-year rule of the present invention generates only one day of error every fifty thousand years. The result is a set of conversion processes that accurately handles dates ranging from Jan. 01, 0001 through Dec. 31, 9999. Dates prior to 1582 are handled as backward projections of the rules defined in 1582.

There are a variety of additional features and options available within the system of the present invention. These features and options have been selected to provide a calendaring system which should perform most any required calendaring function. The many features and options of the present invention are useful per se, and in combination provide a synergistic advantage by virtue of their completeness in that the user will not need to augment the calendaring functions provided.

The system allows the user to choose among ten different holiday tables. This can be useful if the user conducts business with outside areas of commerce, such as foreign commerce, or if various areas of the user's shop observe different holiday schedules.

The system also allows the user to specify dates in any of fifty-two different date formats. The system permits the user to define each day of the week as a processing day or a nonprocessing day. When processing and nonprocessing days are defined, holidays may be taken into consideration. The system also allows the user to select any of the twelve months as the start of the fiscal year, and permits the user to specify day 01 through 28 as the start of the fiscal month. Additionally, the system allows the user to specify whether the FROM-DATE and/or the TO-DATE should be counted in calendaring calculations. The system also provides implicit and explicit access to the current date.

The system offers the user over three hundred functions. These functions fall into three basic groups: utility functions, calendar day functions, and processing day functions. Calendar day functions perform date calculations based on calendar days, and processing day functions perform date calculations based on processing days. Utility functions perform date calculations which are independent of calendar day and/or processing day considerations. Functions provided by the system allow for date calculations based on calendar or fiscal time units, i.e. years, months or quarters.

The preferred embodiment is an apparatus and method for versatile and accurate calendaring. FIG. 1 is a schematic of a computer system utilizing the calendaring system of the present invention. A processing request is initiated at a human interface unit such as a keyboard 100 and is passed via an I/O channel 105 to a computer program 110. Such a request may, for instance, be a request to a database to determine units of a particular type shipped from a particular factory during a particular period. The aforementioned period may be specified as an initial date and a time period from that date. However, the database may only be equipped to handle requests which specify an initial date and a final date. Therefore, communications area 115 provides an interface for transferring the date request to the calendaring program of the present invention 120 which handles date computations. The date computation is performed by the calendaring program 120 and transferred back to the calling program 110 via the communications area 115. The calling program 110 then completes the computation of the request and forwards the answer via an I/O channel 125 to an output device such as a display terminal 130.

FIG. 1b shows an alternate computer system utilizing the calendaring system of the present invention. In this system the calendaring program is accessed directly by the user. A processing request is initiated at a human interface unit such as a keyboard 100 and is passed via an I/O channel 105 to a computer program 110. Such a request may, for instance, be a request for the number of processing days between an initial date and a final date. A communications area (not shown in FIG. 1b) receives the request for the calendaring program of the present invention 120 which handles date computations. The date computation is performed by the calendaring program 120 and transferred to the display terminal 130 via the communications area and the I/O channel 125.

FIG. 2 is view of the interface between the calling program 110 and the calendaring program 120 of FIG. 1a. The calling program 110 formats a request 207 and then transfers control 209 via the conversational area 115 to calendaring program 120 of the present invention. The method of invocation can vary. For instance, in COBOL programming language a "CALL" statement or a "LINK" statement may be used. The calendaring program 120 then receives control of the request 210 and examines the request. If the request is valid, an answer will be formatted 212 and transferred 215 via the conversational area 115 to the calling program 110. If the request is not valid, an error number and text will be formatted instead. When the calling program 110 receives control of execution 217 it examines the return 220 for an error condition before any other operation since if the return code is bad, the other output areas have no meaning. However, if the return code is good, the calling program 110 interprets the answer 225.

There are a number of standards and conventions used within the system of the present invention which are described below:

1. The system treats Sunday as the first day of the week, and Saturday as the seventh day of the week. This corresponds to the arrangement of the days of the week on the calendar. Though the user is able to assign arbitrary numerical values to the days of the week, the first position in fields of seven characters representing days of the week will always represent Sunday, and so on.

2. The number of days that have elapsed since Jan. 01, 0001 is termed the "absolute days". The integer absolute days value 00000001 is defined equal to the date of Jan. 01, 0001, and according to the leap-year rules discussed above the absolute days value 03652056 is then equal to the date of Dec. 31, 9999.

3. The system distinguishes between a calendar day and a processing day. A calendar day is any day of the calendar year and a processing day is a business day or a work day. Processing days are defined for each day of the week, and may take holidays into account.

4. The literal "CURRDATE" may be entered into either the FROM-DATE field or the TO-DATE field (see below), and generates the current date.

5. The system maintains consistency between two basic types of functions. The first basic type of function computes the number of days between two dates. For example there are 3 days between Mar. 15, 1994 and Mar. 18, 1994. The second basic type of function calculates a date based on a starting date and a numerical increment. For example, Mar. 15, 1994 plus 3 days results in Mar. 18, 1994. "FROM-DATE" specifies the starting point; "TO-DATE" specifies the ending point; "DIRECTION" specifies the bearing from the FROM-DATE to the TO-DATE; and "DISPLACEMENT" specifies the actual number of days that lie between the two dates. The principles of FROM-DATE, TO-DATE, DIRECTION and DISPLACEMENT are exemplified in the examples below:

    ______________________________________
    DAYS BETWEEN     DATE +/- N Days
    ______________________________________
    FROM-DATE
             Mar 15, 1994
                         FROM-DATE   Mar 15, 1994
    TO-DATE  Mar 18, 1994
                         DIREC/DISPL +3
    DIREC/DISPL
             +3          TO-DATE     Mar 18, 1994
    FROM-DATE
             Mar 18, 1994
                         FROM-DATE   Mar 18, 1994
    TO-DATE  Mar 15, 1994
                         DIREC/DISPL -3
    DIREC/DISPL
             -3          TO-DATE     Mar 15, 1994
    ______________________________________

    ______________________________________
    A = Always   (Always a processing day)
    N = Never    (Never a processing day)
    E = Exclude  (A processing day only if not a Holiday)
    I = Include  (A processing day, only if a Holiday)
    ______________________________________

    ______________________________________
    MASK          VALUE      DATE
    ______________________________________
    YYDDD
    22005                    January 5, 2022
    YYDDD---      58040---   February 9, 1958
    YYMMDD
    760410        April 10, 1976
    YYMMDD--      490228--   February 28, 2049
    CCYYMMDD      19930605   June 05, 1993
    DDCCYYMM      05199306   June 05, 1993
    ______________________________________

    ______________________________________
    FUNC     TASK         OUT-NUMERIC-PARM
    ______________________________________
    U002     Valid Date?  0 - NO;   1 - YES
    U003     Leap Year?   0 - NO;   1 - YES
    U004     Holiday?     0 - NO;   1 - YES
    005      Processing Day?
                          0 - NO;   1 - YES
    U006     Day of Week  See DOW-STRING
    U007     Absolute Days
                          00000001 - 03652056
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930903     N/A          +0
    19930904     YES          +1
    19930905     YES          +2
    19930906     YES          +3
    19930907     YES          +4
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930903     N/A          0
    19930904     NO (Saturday)
                              0
    19930905     NO (Sunday)  0
    19930906     NO (Holiday) 0
    19930907     YES          +1
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930907     N/A           0
    19930906     YES          -1
    19930905     YES          -2
    19930904     YES          -3
    19930903     YES          -4
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930907     N/A          0
    19930906     NO (Holiday) 0
    19930905     NO (Sunday)  0
    19930904     NO (Saturday)
                              0
    19930903     YES          -1
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930903     N/A           0
    19930904     YES          +1
    19930905     YES          +2
    19930906     YES          +3
    19930907     YES          +4
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930903     N/A           0
    19930904     NO (Saturday)
                               0
    19930905     NO (Sunday)   0
    19930906     NO (Holiday)  0
    19930907     YES          +1
    19930908     YES          +2
    19930909     YES          +3
    19930910     YES          +4
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930907     N/A           0
    19930906     YES          -1
    19930905     YES          -2
    19930904     YES          -3
    19930903     YES          -4
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930910     N/A           0
    19930909     YES          -1
    19930908     YES          -2
    19930907     YES          -3
    19930906     NO (Holiday) -3
    19930905     NO (Sunday)  -3
    19930904     NO (Saturday)
                              -3
    19930903     YES          -4
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930212     N/A          +0
    19930213     YES          +1
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930212     N/A          0
    19930213     NO (Saturday)
                              0
    19930214     NO (Sunday)  0
    19930215     NO (Holiday) 0
    19930216     YES          +1
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930216     N/A          -0
    19930215     YES          -1
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19930216     N/A          0
    19930215     NO (Holiday) 0
    19930214     NO (Sunday)  0
    19930213     NO (Saturday)
                              0
    19930212     YES          -1
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19940706     N/A          -0
    19940705     YES          -1
    19940704     YES          -2
    19940703     YES          -3
    19940702     YES          -4
    19940701     YES          -5
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19940706     N/A          0
    19940705     YES          -1
    19940704     NO (Holiday) -1
    19940703     NO (Sunday)  -1
    19940702     NO (Saturday)
                              -1
    19940701     YES          -2
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19921223     N/A          +0
    19921224     YES          +1
    19921225     YES          +2
    19921226     YES          +3
    19921227     YES          +4
    19921228     YES          +5
    19921229     YES          +6
    19921230     YES          +7
    19921231     YES          +8
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19921223     N/A          0
    19921224     YES          +1
    19921225     NO, (Holiday)
                              +1
    19921226     NO, (Saturday)
                              +1
    19921227     NO, (Sunday) +1
    19921228     YES          +2
    19921229     YES          +3
    19921230     YES          +4
    19921231     YES          +5
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19940701     N/A          0
    19940702     YES          +1
    19940703     YES          +2
    19940704     YES          +3
    19940705     YES          +4
    19940706     YES          +5
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19940701     N/A          0
    19940702     NO (Saturday)
                              0
    19940703     NO (Sunday)  0
    19940704     NO (Holiday) 0
    19940705     YES          +1
    19940706     YES          +2
    19940707     YES          +3
    19940708     YES          +4
    19940709     NO (Saturday)
                              +4
    19940710     NO (Sunday)  +4
    19940711     YES          +5
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19921231     N/A          0
    19921230     YES          -1
    19921229     YES          -2
    19921228     YES          -3
    19921227     YES          -4
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19921231     N/A          0
    19921230     YES          -1
    19921229     YES          -2
    19921228     YES          -3
    19921227     NO, (Sunday) -3
    19921226     NO, (Saturday)
                              -3
    19921225     NO, (Holiday)
                              -3
    19921224     YES          -4
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19921228     N/A          -0
    19921225     YES          -1
    19921218     YES          -2
    ______________________________________

    ______________________________________
    DATE         QUALIFICATION
                              COUNT
    ______________________________________
    19921228     N/A          0
    19921225     NO (Holiday) 0
    19921218     YES          -1
    19921211     YES          -2
    ______________________________________

    ______________________________________
    TIME-PERIOD           FUNCTION-NUMBER
    ______________________________________
    Calendar Year
              Previous  Beginning F01
              Previous  End       F02
              Current   Beginning F03
              Current   End       F04
              Next      Beginning F05
              Next      End       F06
    Fiscal Year
              Previous  Beginning F07
              Previous  End       F08
              Current   Beginning F09
              Current   End       F10
              Next      Beginning F11
              Next      End       F12
    Calendar Quarter
              Previous  Beginning F13
              Previous  End       F14
              Current   Beginning F15
              Current   End       F16
              Next      Beginning F17
              Next      End       F18
    Fiscal Quarter
              Previous  Beginning F19
              Previous  End       F20
              Current   Beginning F21
              Current   End       F22
              Next      Beginning F23
              Next      End       F24
    Calendar Month
              Previous  Beginning F25
              Previous  End       F26
              Current   Beginning F27
              Current   End       F28
              Next      Beginning F29
              Next      End       F30
    Fiscal Month
              Previous  Beginning F31
              Previous  End       F32
              Current   Beginning F33
              Current   End       F34
              Next      Beginning F35
              Next      End       F36
    ______________________________________

                  TABLE 1
    ______________________________________
    Gregorian Date
                  360-day-year Date
    ______________________________________
    02/27/1996    1996/057
    02/28/1996    1996/058
    02/29/1996    1996/059
    03/01/1996    1996/061
    03/02/1996    1996/062
    ______________________________________

                  TABLE 2
    ______________________________________
    Gregorian Date
                  360-day-year Date
    ______________________________________
    02/27/1994    1994/057
    02/28/1994    1994/058
    03/01/1994    1994/061
    03/02/1994    1994/062
    ______________________________________

                  TABLE 3
    ______________________________________
    Julian Date  360-day-year Date
    ______________________________________
    057/1996     056/1996
    058/1996     057/1996
    059/1996     058/1996
    060/1996     059/1996
    061/1996     060/1996
    062/1996     060/1996
    063/1996     061/1996
    ______________________________________

                  TABLE 4
    ______________________________________
    Julian Date  360-day-year Date
    ______________________________________
    057/1994     056/1994
    058/1994     057/1994
    059/1994     058/1994
    060/1994     059/1994
    061/1994     060/1994
    062/1994     061/1994
    063/1994     062/1994
    ______________________________________

                  TABLE 5
    ______________________________________
    360-day-year Date
                    Gregorian Date
    ______________________________________
    057/1996        2/27/1996
    058/1996        2/28/1996
    059/1996        2/29/1996
    060/1996        2/30/1996
    061/1996        3/01/1996
    062/1996        3/02/1996
    ______________________________________

                  TABLE 6
    ______________________________________
    360-day-year Date
                    Gregorian Date
    ______________________________________
    057/1994        2/27/1994
    058/1994        2/28/1994
    059/1994        2/29/1994
    060/1994        2/30/1994
    061/1994        3/01/1994
    062/1994        3/02/1994
    ______________________________________

                  TABLE 7
    ______________________________________
    360-day-year Date
                    Julian Date
    ______________________________________
    057/1996        057/1996
    058/1996        058/1996
    059/1996        059/1996
    060/1996        061/1996
    061/1996        062/1996
    062/1996        063/1996
    ______________________________________

                  TABLE 8
    ______________________________________
    360-day-year Date
                    Julian Date
    ______________________________________
    057/1996        057/1996
    058/1996        058/1996
    059/1996        059/1996
    060/1996        060/1996
    061/1996        061/1996
    062/1996        062/1996
    ______________________________________