When the mood strikes. But do so with full awareness, don't force it. If it's not time, you'll feel it, or if it's time, there would be no internal resistance. In any case when you smoke, pay attention to every nuance, how it makes you feel, the headspace it gives you, and then the after effects, as well as how you feel in the morning afterwards when you wake up. Also how it influences your actions/perception/decisions while on it, and how you feel after it wears off. When you pay attention to all of those things, I think you will be able to tie everything else together yourself.
Enjoy brother, i'm hoping to light one up myself here shortly 8)