Stryd has an internal clock that get synchronized by the phone. The internal clock from Stryd continues to increment time, even when not connected to a phone or watch. However, if Stryd runs out of battery the clock stops.
If Stryd ran out of battery, and get charged again, the clock will start ticking again but the time will be incorrect. When uploading Stryd data with the app on the phone, the activities will have the incorrect timestamp and may appear at the wrong date and time in the calendar.
To avoid this problem, keep your Stryd charged at all times. If you do end up with a depleted battery, connect to your Stryd with your phone to reset time and date.
If you need further assistance, contact firstname.lastname@example.org.