Reinclude simulator time display explanation

Author: WillB97

simulator/index.md

@@ -69,6 +69,26 @@ Within the Webots IDE, there are a few different panels:
 - [Camera Controls](https://www.cyberbotics.com/doc/guide/the-3d-window#navigation-in-the-scene)
 - [Graphics settings](https://www.cyberbotics.com/doc/guide/preferences#opengl) (Useful if Webots is running slowly)
 
+## Time
+
+In the simulated environment, time advances only at the pace that the simulator
+is run. The relation between this time and the real passage of time depends on a
+couple of factors: the speed the simulation is configured to run at and the
+ability of the computer running the simulation to process it fast enough.
+
+You can configure and observe the speed the simulator is running at from the toolbar in webots:
+
+![]({{ site.baseurl }}/images/content/simulator/speed-toolbar.png)
+
+Here the simulation has run for 13.28 seconds, but is currently paused (the
+speed multiplier shows 0.00×). You could choose to step a single time increment,
+run the simulator at real speed (▶), or run the simulator at various faster
+speeds (▶▶ and ▶▶▶).
+
+These differences mean that your code will need to use a different mechanism to
+find the current time or to sleep within the simulation. Find out more by
+heading over to the [simulator programming docs](./programming).
+
 ## Programming
 
 Once you have the simulator installed you can begin [programming your robot](./programming) in the simulator.