By default, the time picker displays minutes from 0 through 59. To restrict the time selections that are available to users, you can configure your application to display intervals of minutes on time controls, instead. Select the Allow time to be displayed in the interval of minutes option and click the corresponding number of minutes: 5, 10, 15, 20, or 30. At run time, the times available for selection are based on this setting. For example, if you set intervals of 15 minutes, a user can select 9:00 AM, 9:15 AM, 9:30 AM, or 9:45 AM in the application.

Select Datetime control , presentation tab , select the checbox Intervals in an hour and select the desired interval.