In my experience, getting dates/times right when programming is always fraught with danger and difficulity.
Ruby and Rails have always eluded me on this one, if only due to the overwhelming number of options; I never have any idea which I should pick.
When I'm using Rails and looking at ActiveRecord datatypes I can find the following
:datetime, :timestamp, :time, and :date
and have no idea what the differences are or where the gotchas lurk.
What's the difference? What do you use them for?
(P.S. I'm using Rails3)