LG v20 User Manual page 120

Tools
118
Timer
The Timer tab can alert you with an audible signal when a set amount of
time has passed.
1. Open the Clock app, then select the Timer tab.
2. Set the desired time on the timer.
3. Tap the Start button to start the timer.
4. Tap the Reset button to stop the timer.
Stopwatch
The Stopwatch tab allows you to use your device as a stopwatch.
1. Open the Clock app, then select the Stopwatch tab.
2. Tap the Start button to initiate the stopwatch.
Tap the Lap button to record lap times.

3. Tap the Reset button to stop timing.