4 weeks flowering sour diesel growth ph flowering time question

Fucking shit hear I go again with ny panic attack I looked at these tichomes I saw slot of amber ones on one bud but t was in the middle I think. So I xhoped it off. Now I'm thinking this shit might be ready so I looked at another area on top bud. Lemme ask u. When is better to harvest when lights go on before. I'm assuming when light hits plants it starts it sux up water or nutes. Am I close to rght. And what's the deal with the whole 24 hours darkness before harvset is that a good idea. What does it incease hormones/thc production or whatever

I hope these ladies aren't over due and are just gonna taste like ass cheese The taste and smell is affected if it's past harvest time?