1. A method of processing a computer source program, comprising the steps of: providing a data declaration extension syntax, wherein the syntax comprises use of a date format attribute to identify the data declaration extension to a compiler and attributes for identifying one of a plurality of Year 2000 solutions; 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 first data declaration extension that identifies a Year 2000 solution and at least one further received statement comprises a second data declaration extension that identifies a Year 2000 solution comprising a field as containing four-digit year data, and wherein the data declaration extensions are in a format of the provided data declaration extension syntax; and compiling the source program into an object program in the memory of the computer, wherein the object program includes instructions for processing and/or invoking procedures on data fields associated with the extended data declarations including characterizing data within the four digit year data field as including four-digit year data.