In most iOS apps that use the spinning picker for hours and minutes in date fields, a double tab on the minutes spinner changes the interval from 1 minute to 5 minutes. This makes it easier to scroll to the desired time, e.g. for setting due date/time.
Certainly seems so, I feel that if anything it should be locked the other way (though having a switchable option is definitely preferable). I rarely find I need that precision when assigning due dates.