For the record...
There was rhyme and reason to the stardate system used in TNG/DS9/VGR. I don't remember how I came to this realization, but, I remember being in study hall in high school, for the better part of a week, figuring out the system.
You take a certain day of the year, say for example, my birthday January 21st...The 21st day of the year...Divide that into 365.25, and you get .0574949 So, if I was alive in the first season of TNG, the my birthdate would have been 41057...And if you divide a 24 hour day up into 10 equal parts (as I was born at 4:34AM), the specific time would have been (after the decimal point), close to 41057.2, which would have been some time just before Encounter At Farpoint.
Don't believe me? Do the math yourself.
As for why they changed it for the Jellyfish computer? Your guess is as good as mine. Incidentally, I was so disgusted with the alternate universe JJ created that I never noticed.