Is it possible to resync the TAG 520, ALGE TIMY &/or the S3 WITHOUT turning them off and on again?

Try this to get the other timers resynced. The S3 will have to be restarted as will the 520.

SYNC FEATURE IN BACKUP AND PC TIMER

1. YOU CAN SYNC ONE TIMY AND THEN USE IT TO SYNC OTHER DEVICES
2. THIS ONLY WORKS WITH BACKUP AND PC TIMER PROGRAM
3. PRESS THE GREEN AND RED “OK” BUTTONS DOWN WHEN THE TIMY APPROACHES THE TOP ON A MINUTE
4. THE TIMY WILL SEND A PULSE OUT THE CHANNEL “0” BANANA PLUGS AT THE “0” POINT