Carrier RG66B3/BGEF Owner's Manual page 13

Example: Setting the unit to turn on after 6 hours, operate for 2 hours, then turn off (see the
figure below)
Your remote display
Timer starts
Current
2PM
time 1PM
Timer is set To turn ON
6 hours from current time
Timer is set to turn OFF
8 hours from current time
3PM 4PM 5PM
6 hours later
8 hours later
Unit turns
ON
6PM 7PM
12
Unit turns
OFF
8PM 9PM