I think Robau was just being casual. He wasn't logging it so there was no need to say blah blah point blah.
I'm inclined to agree, so if we go with that and apply it to the year 2259:
stardate 2259.01=January 1, 2259
stardate 2259.10=January 10, 2259
stardate 2259.100=April 10, 2259