Have a look at the link in my original post, it explains in a bit more depth.
I personally call him every time and ask. You could probably ask in general (speed up my working hours, slow down my time outside of work) but might need to redo it every couple of weeks to make sure you’re feeding energy into the servitor network.
If I’m alone I will call him by tracing his sigil in the air with my forefinger, then I will repetitively trace a circle clockwise or counterclockwise (depending on whether I want time sped up, or slowed down, respectively) while chanting his name. Although I don’t actually “chant” it as such. With most entities you would try and chant their name repetitively and on the same beat/time each repetition. With Fotamecus I “chant” the syllables of his name at random lengths, off beat, and constantly change the length of each syllable.
If you’re not alone you can visualise his seal and focus energy toward it, “chant” (as described above) his name in your head, and/or visualise a clock being smashed with a sledgehammer. Then simply ask him (in your mind) to slow down or speed up time, and whatever other requests you have.
Hope that helps.