option for minute slider to jump 5 mins on drag and drop

when I grag and drop minute slider in estimation dialog it goes by 1 minute. in most cases I estimate by 5 minutes and I would like to see accurate estimation (30 mins, 20 mins). with slider sliding by 1 min it's a little hard to get exactly 30 mins.

maybe I'm being a little bit obsessive here, but an option to enable such behavior would be nice