New moon

Watch news and tools for
collectors and the curious.

Accuracy

How many seconds a day your watch gains or loses, heard through your phone’s microphone.

Sartory-Billard SB10 Jumping Hour 250th Anniversary SB10 Jumping Hour 250th Anniversary
Sartory-Billard · SB10 Jumping Hour 250th Anniversary

SB10 Jumping Hour 250th Anniversary

Change

Somewhere quiet, lay the watch caseback up on something soft. Rest the bottom edge of your phone on the caseback and keep both still.