Once you have a schedule, should you need to add any additional shifts you can use the copy and paste controls to copy an existing shift, or build a new shift and copy that to paste on the various days it will be needed.

To build a new shift, select the day from the calendar on which you would like this shift to occur, and then click the "New Shift..." button in the upper left side of this window.  Set the parameters for this shift including time and required jobs.  Once that is done and you click OK, you will now see this shift on your schedule.

To copy this new shift (or an existing shift) select the date and time so the entire shift is highlighted and then click on the Edit menu at the top of the window.  Select "Copy".

To paste this shift and use on another day, click on the date where you wish to paste the shift from the calendar on the left, click on the Edit menu and choose "Paste".