I find the last two times intriguing for two reasons:
1) Many of them, for instance 2362 and 2381, don't correspond to times. Even on military time, the last two digits will never exceed 59, since there are sixty minutes in an hour. Also, once you get past datapad 6, even the hours don't match up, although this part could be attributed to the possibility that Reach has a longer rotation time, and therefore longer days, than Earth. I don't know if this is either confirmed or invalidated in any canonical source, so the possibility stands. It wouldn't make sense for Bungie to give a location a timekeeping system so alien to our own, though.
2) The numbers on datapads 18 and 19, if interpreted as dates, refer to a year that we all know and love.
Coincidences are always a possibility, but we know how Bungie loves their numbers.