Subtract lunch break hours from Workday.Intl formula?

[YourExcellency]

I need to calculate estimated completion date for various projects. However, I need to subtract lunch breaks, and Sundays so that the formula works correctly. The work continues 24 hours (from 00:00 to 24:00) with three lunch breaks (each 1 hour). Lunch breaks are 03:30 - 04:30; 11:30 - 12:30; 19:00 - 20:00. I am using the formula below; Workday.Intl(C4-1;1+INT(F4/H4/21);11)+MOD(C4;1)+(F4-INT(F4/H4/21)*21*H4)/H4/21;""). However, it always shows an approximate time. I need the date to show me the exact time and minute of the Estimated Finishing time. Any help is much appreciated.

 

[kvsrinivasamurthy]

B4= Product A, C4=Start time (5.12.2022 10:00), G4=planned speed/hour (30.000)
I2=03:30, J2=11:30, K2=19:00, L2=24:00 (formatted for [h]:mm)
Formula in H4

=WORKDAY.INTL(INT(C4),INT((G4+24*MOD(C4,1))/21),1)+MOD(G4+24*MOD(C4,1),21)/24+AGGREGATE(15,6,{0,1,2,3}/(MOD(G4+24*MOD(C4,1),21)/24<=$I$2:$L$2),1)/24-AGGREGATE(15,6,{0,1,2,3}/(MOD(C4,1)<=$I$2:$L$2),1)/24

A	B	C	D	E	F	G	H	I	J	K	L
								03:30	11:30	19:00	24:00
								04:30	12:30	20:00	24:00
		05-12-2022 10:30				30	06-12-2022 21:30