@tychotithonus @robertatcara this was an interesting example of an issue that was recognised well in advance and was clearly defined. For my team at the time there was a lot of testing. Both the 2 digit year storage and the 400 year rule on leap years would have caused issues. Some of them would have been cosmetic but others would have stopped systems working entirely. Some systems needed to manage the roll over correctly, other systems could be turned off and reconfigured on 1st Jan.