Sample code:
type
..
ShedulerPlanner:TPlanner;
...
var
d_base_start,d_base_finish,
d_start,d_finish:TdateTime;
i_start,i_end:Integer;
begin
ShedulerPlanner.Mode.PlannerType:=plTimeLine;
ShedulerPlanner.Display.DisplayUnit:=60;
d_base_start:=encodedate(2018,03,02) + encodetime(10,0,0,0);
d_base_finish:=IncDay( d_base_start,5) + encodetime (12,0,0,0);
ShedulerPlanner.Mode.TimeLineStart:=d_base_start ;//02.03.2018 10:00:00
ShedulerPlanner.Display.DisplayEnd:=( MinutesBetween(d_base_start,d_base_finish) div ShedulerPlanner.Display.DisplayUnit);
// tested Function AbsTimeToCell
d_start:= encodedate(2018,03,03) + encodetime(20,0,0,0);
d_finish:=encodedate(2018,03,04) + encodetime(3,59,59,0);//04.03.2018 3:59:59
// Result i_start<i_end
i_start:=ShedulerPlanner.AbsTimeToCell(d_start);//=44
i_end:=ShedulerPlanner.AbsTimeToCell(d_finish);//=27
// i_end Incorrect.
// for any case when the converted time in the date is less than the time ShedulerPlanner.Mode.TimeLineStart
end