Terminal cut-offs tighten before a long weekend for a simple reason: fewer working shifts have to clear the same volume. The container that would ordinarily gate in the day before sailing needs to be in two days early instead.
We build festival-week cut-offs into the shipping schedule at booking, not as a warning sent the week of. If a lane runs through a long weekend, the plan already accounts for it.
If a booking is already confirmed and a festival week falls inside the transit window, we flag the revised cut-off as soon as the terminal publishes it, not when you ask why the truck left early.