ComponentOne DateTimeEditors for WPF and Silverlight
Value Increment
C1TimeEditor Control Help > Working with C1TimeEditor > Value Increment

Each time a user clicks the increase time or decrease time spin buttons, the value of the control increases or decreases by a program-specified increment. By default, this increment is 00:01:00, or one minute. You can increase or decrease this increment by setting the C1TimeEditor.Increment property. The Increment property will take any value between 00:00:00 (which will disable the spin buttons) and 23:59:59.