Total amount of time for flowering begins at the flowering stage when you see pistils, after the light schedule change.
You can see what the breeder says about “average” flowering times, but realistically some just take longer than others, some less.
Approximately 2 weeks before harvesting. This is a grower preference, it could be different for another grower.
Trichome color is typically the best indicator, but a good visual indicator is when all of the pistils turned 90% brown.