You will be able to select a preferred start time within a timeslot window based on your location (subject to availability). During the booking process, the timeslot window will appear as TIME1, TIME2, TIME3 etc. after the exam name. For example:
RI_SBR_INT_TIME1
Depending on your location you maybe presented with more than one timeslot window. For example:
RI_SBR_INT_TIME1
RI_SBR_INT_TIME2
The lower the number the earlier the timeslot is during the day i.e. if you select TIME1 the exam start times available will all be earlier in the day those available in TIME2.