There are too many variables to give a precise a date that the beer will be ready. Normal : 1 week primary,2 week seconday,3 weeks bottle. I hear 3 months in bottle for extract kit (tins) helps a lot. This is what I leave mine for.
The best way is to keep careful notes of all steps of the process including tasting notes, storages temperatures etx.
Drink 1 per week and keep notes on the taste. Over a period of time you should see the taste getting better and then perhaps worsening.
The next time that you brew use your notes taken previously to determine when to both start tasting and the period of time that your beer will be at its best. No point drinking beer that is not ready or past it prime.
P.S. I keep no notes and really should!!!
Primarys : Ginger Beer, Wheat Beer.
Secondary : Empty
Bottled : all drunk
Drinking : A Lot.
Next Up : Wheat Beer with grainy things