i usually handle mine every day (execpt after feeding) for at least 15 min, but on average a good 30 min to over an hour. i regularly hold mine through an entire 2 hour movie. the key is letting them do as they please and not wigglin your fingers all over them if you get what i mean.

if they are eating well and just kind of lazily move round when being handled they re in a good mood and can be handled as much as you like really.

if they arent eating, or constantly try to dash away or strink when handled they are stressed out and you should leave them alone in the cage and make sure the temps etc are all correct.