Reservation Preset End hides the end date form field when making a Reservations and automatically adds the configured number of hours to the Reservations start time. Users only see one date/time, but the reservation actually has an end date/time. This end date/time MUST be valid. If your hours of operation are configured to end at 5PM and Preset End is configured to make all reservations 1 hour, it will not be possible for a user to create a reservation that starts at 4:30PM.
To configure Reservations Preset End, you must unlock the Reservations Date field using the Advanced settings in the Admin Configuration.
Once unlocked, edit the field to make the end date optional.
Normally the Date module add a checkbox to hide/show the end date field in the form. The Preset End module hides that option.