Re: Could stardates make some sense?
There is also evidence of alternate timekeeping systems, with the Mitchell/Dehner dossier numbers (1087.7 and 1089.5) being about two years apart, and like I said, JJ stardates are also a candidate. The presence of various systems, including calendars of other Federation members, is probably alleviated by the universal translator and the advanced computer, taking care of any conversions for the average user.
Beautiful in-universe explanation.
(However, there was no calendar date reference to Kirk's era in TOS other than the one "200 years" - from then / 1966).
"The first duty of every Starfleet officer is to the truth, whether it's scientific truth or historical truth or personal truth! It is the guiding principle on which Starfleet is based! Jean-Luc Picard