How much left?

Hi guys!
I think the plant is about 4 weeks into flowering. Does it look like that and how much approximately left? 3-4 weeks?
Some of the bigger leafs have started to go "rusty" as you can see from the bottom of the picture, should do act on it or just ignore until harvest?

If you start losing a bunch of leaves you might need to take care of it but usually you can lose 10-50% of your fan leaves as flowering comes to the end. Once you start seeing the buds fill in and the hairs retract you have another week or two, looks like maybe a month or so more but it is difficult to tell.

Looks like you have a month at the least 6-7 weeks most. Harvest time is very strain/size dependent.

Air hit it, I was going to say at least 4 weeks more.