A timer in Premiere Pro is a tool that allows you to track the duration of a clip or sequence. This can be useful for a variety of purposes, such as ensuring that your clips are the correct length, or for creating timed effects.
To start a timer in Premiere Pro, simply click on the “Timer” button in the Timeline panel. This will open the Timer window, which will allow you to set the start and end times of the timer. You can also choose to have the timer run forwards or backwards.