The Turn Back tool can be used to alert you when to turn back on a hike to return at a specific time.
You can set the return time by clicking the input field and selecting a time from the time picker. The return time is the time that you want to return back to your current location if you start the hike now.
Once the return time has been set, an alert will be displayed a little before halfway through the hike to remind you to turn back if you want to return on time. The time until the turn back time is displayed at the top of the screen.
You can choose to use the alarm audio channel for this alert by enabling Settings > Turn Back > Use alarm for turn back alert. This will play a sound as an alarm even if media and notifications are muted.
If you click the "Return before dark" button, the return time will be set to sunset. This is useful if you want to make sure you return before it gets dark.
You can cancel the alert by clicking the "Cancel" button at the bottom of the screen. This will clear the return time and the alert.