The sentence, and its three parts

It is one sentence and it has three specified parts.

A cue that actually happens, at a time you do not have to remember. A place. And a first action small enough that it does not trigger the feeling.

When I have finished Maghrib, I will sit at the desk, open the file, and read for two minutes.

Notice what is not in it. No duration, no target, no chapter, no promise about how much you will get through. Those belong to a different sentence and they are what makes this one fail.