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.

Ole Mathiesen Navy Diver GMT 40 OM10.40AGMT.NA
Ole Mathiesen · OM10.40AGMT.NA

Navy Diver GMT 40

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.