One relay with a form A (Common/Normally Open) contacts.
The output of Timer 1 drives the relay coil.
The output of Timer 2 goes to the safe light on one side and the the relay C contact on the other. The other wire of the safelight is wired to the 'NO' contact of the relay.
For the safe light to be one both timers must have energized their safe light output AC sockets.
It is possible to do it with no relays - but you don't want to try it as it has a good chance of making a short circuit - and violates every wiring code on the planet.
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The reason for switching the safelight off is to:
1) Make focusing easier as there is more contrast on the paper
2) Make it easier to position dodgers and burners
3) Allow the use of meters and analyzers as the safelight illumination interferes with the readings