7. A method of processing a computer source program, comprising the steps of: providing a data declaration extension syntax, wherein the syntax comprises use of DATE-FORMAT to identify the data declaration extension to a interpreter and provides keywords for identifying one of a plurality of windowing techniques and provides fields for specifying ranges of years; receiving a plurality of programming language statements comprising a source program into a memory of a computer, wherein at least one of the received statements comprises a data declaration extension requesting a Year 2000 solution selected from a plurality of windowing techniques, and wherein the data declaration extension is in a format of the provided data declaration extension syntax; and (b) processing the source program with an interpreter, including invoking procedures on a data field associated with the extended data declaration according to the Year 2000 solution requested in the data declaration.
8. A method as recited in claim 7, further comprising the steps of: (a) identifying data declaration statements relating to year values in date fields of the source program; and (b) modifying at least one identified data declaration statement to add an extension requesting a Year 2000 solution to be applied to the year value associated with the statement; and wherein said step of receiving comprises storing the modified data declaration statement in the memory of the computer.