System and method for modifying and operating a computer system to perform date operations on date fields spanning centuries

摘要

The present invention relates to a method for modifying and operating a computer system to perform date operations including the steps of storing at least one subroutine for performing the date operation, modifying the application program to include a call to at least one of the subroutines, the call operative to pass at least one date field representative of at least two dates to the subroutine which has been called, wherein the subroutine determines which of the at least two dates corresponds to the date field according to a predetermined criteria performs a date operation on the date field, and returns a code to the application program for use by the application program in its further operations.