I have managed to find a fairly simple solution that works well enough for our needs:
I just made a value list with the wanted start hours, and in the layout Mini Window Edit Appointment, i dispaly the field ApptTimeStart as a pop-up menu (+ Include other). Thus, people can then easily chose the standard starting times.
And I made ApptTimeEnd field have the Auto Enter Calculated value ApptTimeStart + Time ( xx; yy; 0), so that the appointment will have the right time limit
Just in case anybody else have sort of the same needs
BUT THEN A QUESTION:
Is there a way to recalculate the end time every time the start time changes, but still have the possibility to put in an other end time the few times this is needed?
So that if someone first puts in 08:00, but later changes this to 11:00, the end time will automatically change as well? (So that the appointment does not show Start time: 11:00. End time: 08:45)
I have seen that you often put several fields and other objects on top of each other, but still on the same spot. Would that be the way to solve this? Or is a script better?
Is one solution to make a calculation field that normally changes with the Start time, but somehow being able to modify this field, or make access to an other field on the same spot?