Find Min Time in Sql

Question

ShiftMst
shiftID	Name	startTime	EmdTime	isNightshift
1	Def	14:30	01:30	TRUE
2	test	09:30	18:00	FALSE
3	test1	23:58	6	TRUE

Find The Min Time From Table Permissible consider shift table

tblPermissibleTime
	shiftID	Starttime	EndTime	Mode
	1	14:00	15:00	In
	1	18:00	18:15	out
	1	18:16	18:30	in
	1	00:30	02:30	out
	2	09:00	10:00	In
	2	00:00	00:00	out
	2	17:30	18:30	out
	2	00:00	00:00	in
	3	23:28	00:28	In
	3	05:30	06:30	out
	3	23:00	01:00	out
	3	02:00	03:00	in

OutPut
shiftID	StartTime
1	14:00
2	09:00
3	23:00