J.T.
Was this the first day this happened or has it been going on awhile? This may be something to consider. Has something changed at the daycare? It sounds like you're doing the right thing - a 'time out' kind of consequence with an apology. Does he have other kids his age at the daycare? Are there enough toys and activities or could he be acting out of boredom?
I am a director of a center based child care and a new mom myself. Feel free to e-mail me ____@____.com LUCK!