AVIlgh - I dont claim to be a great expert and so will take your word on the number of weeks
Onan, the legality of where the dope came from is immaterial, after all, its legal to drink a bottle of vodka for breakfast, but if you were caught in a cockpit (or behind a wheel), you could still be done for it (and rightly).
On this kind of subject, I have often wondered how many people would be left on an aircraft if the captain's announcement went along the lines of '
'Good morning ladies and gentlemen, this is the captain here and I will be flying the aircraft to xxxxx this morning assisted by Fred in the right hand seat. After we finish our gin and tonics, we will be taxing out to the westerly runway and taking off before turning south en route to xxx. We will be talking to you later in the flight after the cabin crew bring in our refills and take away the empties. Until then sit back and enjoy our hospitality - I know we will !! '