Without a scope, there's several changes that will show when the harvest window is open. The pods that form below buds will swell and ooze, the hairs turn orange and recede, less glistening of trics under bright light to naked eye.
Upper buds that may get more light may be ahead a bit on maturity with lower buds some days behind.....
Some of us older stoners like the 'knock you on your ass' couchlock! There's a reason stoners always say 'another week or two'....