hmm
that fren u were so worried abt last night??

okie... well... whenever we make someone angry because of our insensitive comments, we can juz wait for some time, fastest is ard 1 day (based on experience) and slowest, a few days, to 1 mth, depends....
but of course, it depends entirely whether that person wants to stay angry or not lah....
as for apology, at the moment u say, it's equivalent to void, because anger cancels it out, so u can take ur best bet, after a few days sms a cute msg or what, then if possible, ask out for dinner or wat loh, at least not so bad for an apology.....
note, level of apology depends on u, how sincere does not mean how many things u do.