A timer can be a critical element to implementing different types of gameplay. Here you will find a couple different solutions for how to implement a timer. The provided videos are thanks to great how to material creators from the community.
Using a While Loop
The two videos found on this page show timers created using a while loop. Both show the use of a custom timekeeper procedure. In one instance it runs concurrently to your first method code so is a total time of the world running.
Using the TimerListener Event
Another approach to building a timekeeper is to use the time listener event to construct the timer. To do this you use the event to trigger a custom procedure to decrement the time variable each time the event is triggered (set it up for one second increments). You can learn more about this approach by reviewing the Introduction to Events, Using Variables, and the Deign Process Games lessons.
A demo world is attached to this page for a rover game. In our world the timer is connected to a game is active state that can be turned off when the timer reaches zero. We hope to add a video showing how this is implemented soon as it may be a little difficult to navigate the implementation.
Thank you to everyone for creating and sharing your instructions. If you know of other great resources for a timer or timekeeper implementation please share.