for dd1 i was in talks to return part-time (new role) which never got off the ground because they couldn't get it through budget. (this was when she was about 1 year). when the job fell through i wanted another bubba, so just got pregnant instead.
DD2 i wanted to go back when she was about 15m but my daycare had no spots so i waited until the New Year, then slowly started applying. it took a few months, but i started a new job last week. dd2 is 22mo now.