Most precise lunar phase wristwatch
- Who
- IWC Schaffhausen, Branch of Richemont International S.A.
- What
- 1 in 45,361,055 day(s):hour(s):minute(s):second(s)
- Where
- Switzerland
- When
- 30 April 2024
The most precise lunar phase wristwatch is the Portugieser Eternal Calendar by IWC Schaffhausen (Switzerland), with a deviation of 1 day in 45,361,055 years, as validated on 10 June 2024.
A moon phase or lunar phase watch displays the current phase of the moon as it appears in the sky, going through the cycle from new moon to full moon and back in approximately 29.5 days.