From the Booking Summary page:
Click on the Booking Date
Make the required change
Optional - select to shift any attached Events or Groups
Click Apply
Additional Information
If working with Groups, any existing blocks will remain on the new dates. If you have extended or shortened the Booking you will need to edit the Group departure date and add any additional blocks. In the example below, the Booking has been shortened upon the date change, however the Departure date on the Group remains the same.
If you wish to select a specific time, uncheck 'all day'.