The NHL has canceled all games until December 14th, along with the Winter Classic and the All-Star Game. For the Boston Bruins, that leaves 53 games on the schedule. And that's enough for a legitimate regular season. But what is the bare minimum number of games for a season?
I put the number at 31. Each team could play 16 divisional games (4 per opponent), then 10 games in the conference (1 per opponent), then 5 games against the other conference (each division in the Eastern Conference would face another division in the Western Conference, so for example the Northeast Division could play the Pacific Division). 31 total games. Just enough to determine divisional winners, and the top 8 from each conference.
The Bruins would have 31 games left on their schedule on February 6th.
Another possible answer is a 36 game schedule, with 16 divisional games and 20 conference games (2 against each opponent). There'd be no interconference games.
If it's determined that a 40+ game schedule is required, then the deadline for that would be around January 15th. Not to mention the time needed for training, practice, cuts, et cetera. I think 40 is what the NHL might consider a minimum.
I'd guess that the deadline for getting a deal done is the end of this month. If the NHL and NHLPA can't come to terms by New Year's Day, then there will be no hockey until next winter. We are approaching the Zero Hour.