Freeze change in a window you can name

The busiest stretches are the worst time to carry out change, because a fault has the least room to be noticed and reversed. A freeze window turns that intuition into a rule with a start and an end.

Name the window in advance

A freeze declared reactively, once something is already breaking, arrives too late to keep ordinary change out. Put the window on the calendar so it is known before it starts.

Define what still lands

A freeze that blocks everything also blocks the fix for a live fault. Write down what counts as an urgent repair, so the rule stops ordinary change without stopping a cure.

def blocked(freeze, deploy):
    return freeze.active and not deploy.urgent

Lift with a watch

When the window ends, do not hand the whole change queue back at once. Watch the first change that was held before the queue is fully open.