How many minutes did the shortest war in history last?

How to get close to this number

For a record minimum, ask what the shortest possible version of the thing is. A war needs a declaration, an exchange of fire and a surrender; the fastest that sequence can physically run, when one side has overwhelming naval artillery and the other has a palace, is under an hour. Reasoning toward the floor of a category is a different skill from estimating a typical value, and it is the right one here.

The trap is imagining that "shortest war" still means something recognisable as a war. It does not: the explanation gives the start and end times to the minute, which is only possible because the entire event fits inside a single morning. Records at the extreme edge of a category usually turn out to be edge cases that barely qualify, and that is the most useful thing to know about them.

What counts as a war between sovereign states is doing real work in this record. Skirmishes, colonial actions and undeclared conflicts are excluded by definition rather than by duration, and several shorter armed exchanges exist that simply are not classified this way. The record is as much about the classification as about the fighting, which is why it is attributed to a records body rather than to a historian.