There's also another Year 20XX problem lurking out there.
A lot of mainframe code that was fixed for Year 2000 had two-digit years in the data, that was converted to a four-digit year by adding 1900. The "fix" for a lot of that was to say if it was less than 70 (or whatever cutoff handled all the dates for the application), add 2000, otherwise add 1900. 72 => 1972, 00 => 2000, 13 => 2013. This fails in 2070, with 2070 being reported as 1970 again.
That same software is untouched 13 years later... I don't have hopes for it being updated soon.
A lot of mainframe code that was fixed for Year 2000 had two-digit years in the data, that was converted to a four-digit year by adding 1900. The "fix" for a lot of that was to say if it was less than 70 (or whatever cutoff handled all the dates for the application), add 2000, otherwise add 1900. 72 => 1972, 00 => 2000, 13 => 2013. This fails in 2070, with 2070 being reported as 1970 again.
That same software is untouched 13 years later... I don't have hopes for it being updated soon.