I got 11+ upvotes and only 29 rep for an answer but my daily reputation was only at 156. That's 44 short of the daily cap! I'm trying to make 20k before the Boston Dev Days, too!
From the FAQ:
A maximum of +200 reputation may be gained per day. Accepted answers are immune to this cap (source) as are bounties (source). This immunity applies only to answers accepted and bounties received after reaching the cap.
(A new day starts 0:00 UTC == 7pm EST == 4pm PST == 1am CET).
Sort of. The days that the rep cap mechanism knows about and the days that the rep history knows about are different. So it winds up looking like you didn't get all your rep for the day, but you did get it all, for some value of "day" (i.e. some 24-hour window, which I think cuts off at 8:00 PM GMT-5).