I was wondering if it is possible to directly control the case fan included with some of the Raspberry Pis. Lots of posts tell you how to turn it on or off when the Raspberry Pi gets to a certain temperature, but I want to use it for other purposes.
Is there a way to turn the 2 pin GPIO fan on or off depending on the time for example?
That will depend entirely upon how the fan is wired, and what type of fan it is. Since you didn't provide these details, the only answer you can get is something like this:
Assuming your fan is powered from the 3.3V bus, and its current is limited to a "safe value", the answer to your question is clearly, "Yes". WRT wiring your fan, another answer here contains a schematic that may be useful.
