” with 99 it went to :0”
Nope. Date functions did it work that way. Date functions would store 2000 as “00” which the computer could not determine it was 2000.
You are mostly correct. The biggest problem was with records that need to be sorted chronologically, such as financial transactions. When 99 became 00, the newer transactions were out of sequence and treated as older when returned by the sort routines.