They were expecting it to start on Friday, and the earlier date made for a busy day of preparations.
The special teams unit was on the ice a half-hour early while the main practice went a full hour on Wednesday.
"We weren't really planning on playing a game (on Thursday), but it all works out better that way," said forward Max Pacioretty. "We were trying to cram in a bit of system stuff as well, so it was a good practice.
"We found out (Tuesday) night. I like it better that way. There's a little less time to think. We're jumping right back into the action. I think that's when I play my best hockey, when I'm not thinking."
Although the NHL had not released a schedule, Canadiens general manager Marc Bergevin mentioned a Friday start in a television interview this week. The opener was moved up reportedly because Northeastern University has graduation ceremonies at the TD Garden on Friday morning.
Game 2 is expected to be played Saturday at 12:30 pm ET, although that has not been confirmed.
Pacioretty likes that, too.
"I like playing afternoon games," he said. "No meetings in the morning. Not thinking too much about the game. Just going out and playing."
The Canadiens will have had eight days off between games. To break the monotony, they held a simulated game day on Monday, with a morning skate followed by an intra-squad game at night. Then they took Tuesday off.
"I'm about ready to stop practising and start playing," said goalie Carey Price.