The timings for all guests within a reservation are entered in the expander Additional data, sub-expander Arrival/departure time.
Figure 12: ETA and ETD
Timings for individual guests or sharers are entered in the
expander Edit data
(available in the reservation, control center, room rack, arrival summary,
etc.). Simply click the Timer-button 
next to the arrival or departure date
and enter the time. Click Modify to save the timings.
Figure 13: Individual ETA for a guest