Playoff fixtures are confirmed at very short notice while regular-season dates are published months ahead. The difference comes from a bracket whose shape is unknown until it resolves.
Series length cannot be predicted
A best-of-seven series ends after four, five, six or seven games, and every subsequent round's start depends on when the previous one finished.
Scheduling a later round in advance would require assuming a length, and the assumption would be wrong often enough to make the published dates meaningless.
Leagues instead publish a window and confirm exact dates once the preceding results are known, which is why the calendar firms up round by round.
Broadcast slots must be allocated between concurrent series
Several series run simultaneously in early rounds, and a broadcaster wants to avoid two of its games clashing while filling as many evenings as possible.
Games are therefore staggered across each day and across the week, which means one series may play on consecutive nights while another waits.
Teams experience that as uneven rest, and the imbalance is a scheduling artefact of trying to fill windows rather than a competitive decision.
Arena availability reappears as a problem
Buildings booked for concerts and other events months ahead may not be free on the night a series requires, and those bookings are contractually difficult to move.
Where a conflict cannot be resolved, the game shifts by a day, which then cascades into the rest of the series and sometimes into the next round.
Venues serving multiple teams face the sharpest version of this, since two postseason runs can demand the same building on the same evening.
Travel between games sets a floor
Rules provide minimum rest and travel time between games in a series, which constrains how tightly consecutive games can be placed when teams are far apart.
Charter travel has compressed those requirements compared with earlier eras, allowing schedules that would once have been impossible.
The compression is used, unsurprisingly, to fit more games into the same broadcast window rather than to give players longer between them.
Short notice is felt by everyone but the broadcaster
Supporters cannot plan travel or accommodation, and ticket sales compress into a few days, which changes who is able to attend.
Teams face the same problem operationally, arranging staffing, catering and security for a date confirmed less than a week ahead.
The flexibility all of that provides accrues to the rights holder, which is the party whose requirements the confirmation process is built to satisfy.
