Without arguing the relative merits of storing a datetime this way…
If you had a column where you stored AM or PM what would you call that column?
EDIT:
I should have figured that there’d be a group of you who couldn’t resist being snarky about the idea… Nowhere do you see that I’m about to do this, that I want to do this, that I’m unclear of the myriad of reasons not to do this… but still some of you feel compelled to be priggish and concern yourselves with how much smarter you are rather than take the question for what its worth and offer something useful.
I’m also very pleased that so many aren’t deserving of this slur and brought forth some great ideas. Thanks for the thoughts.
Most groups of values have names, the values from 1-24 are known as hours, from 1-12 Months, etc. But for AM/PM what’s the name for group, for the collection, for the domain… and they are clearly not ‘meridiem’ because that is the name of a single point in time Noon. That would be like calling AD and BC either Christ’s or Lord’s. Whereas BCE or CE would probably fit into an ‘Era’ column.
I’d call it meridiemoffset and store 0 or 12 in it. Easy to convert to AM or PM as necessary, but the main feature is that you can easily calculate the real hour by addition, even inside the SQL statement (which makes sorting easier and more obvious).
-Adam