There was a clock calibration issue in early versions of the Harmony's software that caused it to gain time.
Solved With an Update
The clock in its factory form could gain time even as fast as a few minutes per day. If you noticed that your Harmony runs fast, it's likely that's the clock is running on an outdated system version.
To have your Harmony start keeping time accurately and get access to multiple other bug fixes and improvement, please update your clock's OS using our desktop application Mudita Center.