From Jobs / Dispatch
Double click on the job that you want to multi book.
On the top panel select Multibook.
Click once on each day that you would like add the job to the schedule. You can also click and drag on consecutive days to add.
Confirm each required date is listed on the right hand grid.
If you need to remove a date double click on the date to remove it from the list.
Select "Close" to close the window and return to the job entry screen.
You can then "Save" the job which will save all additional dates.