Set the scheduling units for duration

​​​Change the default duration units

  1. On the File menu, click Options, and then click the Schedule tab.
  2. Under Scheduling options for, in the Duration is entered in box, click a duration unit.
  3. To use this setting in current project, click OK.

Note  The default duration unit is days, but you can change it to minutes, hours, weeks, or months, just select from list the desired units and press OK.