From the blog post announcing the FitbitOS 4.1 SDK it sounds like custom always-on clocks are in the works: https://dev.fitbit.com/blog/2019-12-19-announcing-f

From the blog post announcing the FitbitOS 4.1 SDK it sounds like custom always-on clocks are in the works: https://dev.fitbit.com/blog/2019-12-19-announcing-fitbit-os-sdk-4.1/ https://dev.fitbit.com/blog/2019-12-19-announcing-fitbit-os-... (Disclosure: I work at Fitbit but not on any of the SDK or device stuff. This is my own personal opinion and should not be considered the official position of my employer.)