Hi Julius
Enhance the component, redefine the method and comment the line.
'ADD 500 TO lv_start_time'
in Component/view CLEAR_HEAD/ClearSchedule
method DO_VIEW_INIT_ON_ACTIVATION of class CL_CLEAR_HE_CLEARSCHEDULE_IMPL
Refer to the following link
How to set the Schedule Merge Time and Date in ... | SCN
Bernadette