As a farmer i would like to see some high end materials have a longer ‘germination’ period then the lower end, even on a lower end harvesting once daily is fast, really really fast.
Considering amount of crops and micro management, having a week for max time and 2 days for lowest would give time for other aspects of the game.
Need more info to really answer, but the topvoted ranges seem reasonable. Not sure why 24 minutes is a choice though? Kind of an odd number. I’d go with 15 minutes to a week.