Formula - Calculating Must Clock out time

[gd6noob]

Hi guys,


Im trying to figure out how to calculate this.
From the table below in column M, I would like to figure out the Must Clock Out time. From the first "In" time in column E.

1. If there are "Out" time in column H, K and L, then column M would day "Clocked Out"
2. If there are "In" times in column I or K, then it would cancel out the Out times in H and K as it would indicate they would still be onsite.
3. Column D, if the shift starts with N, and there is an In and Out in colums F and G, then column M would say Clocked Out".
4. If the last column from left to right is "In" that is populated, I would need to calculate all the hours worked (minus the out time, as this is there break) to not exceed 12 hours in a single shift.
5. The current formula in column M also has a 15min buffer until reaching 12hours.

12 Hour Tool V4.0 (Make Copy).xlsb
	A	B	C	D	E	F	G	H	I	J	K	L	M
1	Employee ID	Employee Name	Manager	Shift	In	Out	In	Out	In	Out	In	Out	Must Clock Out By
2				NB3C1915	4:01:00 AM	6:05:00 AM							4:16:00 PM
3				NF6C1830	4:01:00 AM	5:40:00 AM							4:16:00 PM
4				NB3C1900	4:04:00 AM	5:30:00 AM							4:19:00 PM
Current Shift Clock Punches

Cell Formulas
Range	Formula
M2:M4	M2	=IF(E2 = "","No Clock In Time",IF(F2<>"",E2+TIME(12,30-15,0),E2+TIME(12,0-15,0)))

Thanks in advanced for any help.