Occupying oases...

When I have occupied three oases, which one runs out first. The one at the top of the list or bottom? I heard that the lvl 3 oasis only produces for 3 days. Lvl 4 for four days and so forth. Thanks for taking the time to reply?

What you heard is right. Every 24 hours you hold an oasis, it's level decreases by one.

When it reaches lv0, you automatically resign the oasis

If you want the oasis to last release it every 23 hours then take it back and it will never go lower than the lvl u take it at

Yeah whatever the lvl that iz how long it shall last and thank you wadro i had never though of that

Exactly what wadro said, but doing it every 23 hours will get to the point where you'll need to sleep before that point hits. If you have the spare time, you can drop it twice on the days where the time to retake subs gets to the point of nearing your sleep time.
Don't do like some people do and leave your troops in those oasis's you take to avoid your hunt showing on screen. People, like me, do scout owned oasis's and forts for troops that people leave in them