Methods for encoding decoding and processing six character date designations for the year 2000 and beyond

A computer-implemented method for decoding a calendar date from a format suitable for a digital data processor of the type that stores such combinations in memory adapted for holding a sequence of six characters, the method comprising the steps of

• (a) examining a sequence of six characters to determine whether the first two digits are equal to 99, and if so, whether the last four characters are one of the group consisting of
• (i) four digits in the range from 1232 to 9999 inclusive, and
• (ii) four characters, at least one of which is non-numeric,
• (b) responding to a negative determination in step (a) for generating a four-digit number representing a calendar year, in which the first two digits are 19 and the second two digits are the first two digits of the sequence, generating a two-digit number representing a calendar month, in which the month is represented by the third and fourth digits of the sequence, and generating a two-digit number representing a calendar day, in which the day is represented by the final two digits of the sequence,
• (c) responding to a positive determination in step (a) for generating a four-digit number representing a calendar year, said number being greater than 1999, for generating a two-digit number representing a calendar month, which number is between 01 and 12 inclusive, and for generating a two-digit number representing a calendar day, which number is between 01 and 31 inclusive.