How many days did the Berlin Airlift last?

How to get close to this number

Reason from the logistics rather than from the politics. Supplying an entire city by air is not a raid, it is a permanent replacement for road and rail, and it has to continue until the blockade ends. Blockades are political instruments measured in months, not days, so the answer is on the scale of a year or more — and the airlift in fact outlasted the blockade itself, as stockpiles were built up before it was wound down.

The figure that makes the scale real is in the explanation: at peak, an aircraft landing every thirty seconds, continuously. That is a rate that leaves no room for error, weather delay or unloading backlog, and it is the detail that explains why the operation is studied as a logistics achievement rather than as a military one. Sustained rate, not total tonnage, is what was unprecedented.

Dates for the operation vary slightly between sources because the blockade, the flights and the formal end of the operation happened at different times. The figure here follows the air force's own historical record of the operation's duration, which is the most defensible single span, and it is a good example of why an event duration always needs to say which bookends it is using.