Y2K problem for days-between-dates for TI-84 series calcs

[Don Shepherd]

(05-08-2017 12:13 AM)matthiaspaul Wrote:  Don, if you can document this in better details, this might be interesting info to be included in this Wikipedia article:

https://en.wikipedia.org/wiki/Time_forma...orage_bugs

Greetings,

Matthias

Thanks Matthias.

That widipedia page already contains this:

Follow-on problems caused by certain temporary fixes to the Y2K problem will crop up at various points in the 21st century. Some programs were made Y2K-compliant by continuing to use two digit years, but picking an arbitrary year prior to which those years are interpreted as 20xx, and after which are interpreted as 19xx.

For example, a program may have been changed so that it treats two-digit year values 00–68 as referring to 2000 through 2068, and values 69–99 as referring to 1969 through 1999. Such a program will not be able to correctly deal with years beyond 2068.

I wouldn't exactly call TI's method a "bug"; it does calculate days between dates correctly within its abbreviated range. I think it could more accurately be described as "shortsighted." If TI intends to continue the TI-84 line into the future, I suspect they will have to change this method in the next few years.