From clear? Usually a couple of weeks at least. Depends on when they start putting on trichs.
I use a number of other metrics by which to gauge doneness, if that's what you're after. Some strains just don't follow the progression we're taught to expect: clear-->cloudy-->amber.
- New pistils vs red hairs: is it still popping a lot of new pistils, or is it mostly red hairs with a few new pistils here and there?
Bananas? Many girls just throw them when they're nearing doneness.
Bud building & swelling, or just ripening? In other words, are the buds continuing to get bigger and put on weight, or have they 'stalled'?
Adding these other metrics to the progression of trichome color allows you to better gauge doneness, and allows you more flexibility in how you make that assessment.
The last for me might be measuring Brix, and perhaps, NH4:NO3 ratios.