2. Structure of Y10K Solution

Any Y10K solution should have the following characteristics.

2.1. Compatibility

The format must be compatible with existing 4-digit date formats. Y2K compliant programs and standards must continue to work with Y10K dates before the year 10,000. Y10K compliant programs can gradually be developed over time and coexist with non-Y10K compliant programs.

2.2. Simplicity and Efficiency

Y10K dates must allow dates after 10,000 to be easily identified. Within a program, there must be a simple procedure for recognizing the Y10K dates and distinguishing them from legacy dates.

2.3. Lexical Sorting

Y10K dates must be sortable lexically based on their ASCII representation. The dates must not require specialized libraries or procedures.

2.4. Future Extensibility

Y10K dates must support arbitrary precision dates, and should support dates extending arbitrarily far into the future and past. Y10K dates from different eras and with different precisions must be directly comparable and sortable.

2.4.1. Environmental Considerations

The known universe has a finite past and future. The current age of the universe is estimated in [Zebu] as between 10 ** 10 and 2 * 10 ** 10 years. The death of the universe is estimated in [Nigel] to occur in 10 ** 11 - years and in [Drake] as occurring either in 10 ** 12 years for a closed universe (the big crunch) or 10 ** 14 years for an open universe (the heat death of the universe).

In any case, the prevailing belief is that the life of the universe (and thus the range of possible dates) is finite.

2.4.2. Transcending Environmental Considerations

However, we might get lucky. So, Y10K dates are able to represent any possible time without any limits to their range either in the past or future.

Y10K compliant programs MAY choose to limit the range of dates they support to those consistent with the expected life of the universe. Y10K compliant systems MUST accept Y10K dates from 10 ** 12 years in the past to 10 ** 20 years into the future. Y10K compliant systems SHOULD accept dates for at least 10 ** 29 years in the past and future.