subtracting values only after a change

[dmheller]

I have included some data but on 3/30/22, i had to hard type the value but i have an equation in where the value 66 and 78 are and it is very bad. It looks at column B and C and D and E those are hours and min and then tries to look for a change. It only looks 4 days down and i could write it longer but is there a better way to find the change and then show the difference? So you can see 3/24/22 to 3/28/22 the change is 60 minutes and 49 minutes. then from 3/28/22 to 3/30/22 change was 66 and 56 minutes then my equation didnt work for 3/30/22 because it was a 5 day gap so i hard typed that in and put a new value in 4/4/22. It is a mess but any help would be great.
thanks.
=IF(C90="","",IF((C89*60+D89)=(C88*60+D88),0,IF(AND((C89*60+D89)=(C90*60+D90),(C89*60+D89)=(C91*60+D91),(C89*60+D89)=(C92*60+D92),((C93*60+D93)-(C89*60+D89))>0),(C93*60+D93)-(C89*60+D89),IF(AND((C89*60+D89)=(C90*60+D90),(C89*60+D89)=(C91*60+D91),((C92*60+D92)-(C89*60+D89))>0),(C92*60+D92)-(C89*60+D89),IF(AND((C89*60+D89)=(C90*60+D90),((C91*60+D91)-(C89*60+D89))>0),(C91*60+D91)-(C89*60+D89),IF(((C90*60+D90)-(C89*60+D89))>0,(C90*60+D90)-(C89*60+D89),0))))))

3/24/2022​	396​	43​	367​	41​	60​	49​	2340​	1911​	4251​
3/25/2022​	396​	43​	367​	41​	0​	0​	0​	0​	0​
3/26/2022​	396​	43​	367​	41​	0​	0​	0​	0​	0​
3/27/2022​	396​	43​	367​	41​	0​	0​	0​	0​	0​
3/28/2022​	397​	43​	368​	30​	66​	56​	2574​	2184​	4758​
3/29/2022​	397​	43​	368​	30​	0​	0​	0​	0​	0​
3/30/2022​	398​	49​	369​	26​	78​	72​	3042​	2808​	5850​
3/31/2022​	398​	49​	369​	26​	0​	0​	0​	0​	0​
4/1/2022​	398​	49​	369​	26​	0​	0​	0​	0​	0​
4/2/2022​	398​	49​	369​	26​	0​	0​	0​	0​	0​
4/3/2022​	398​	49​	369​	26​	0​	0​	0​	0​	0​
4/4/2022​	400​	7​	370​	38​

 

[dmheller]

sorry there is an edit that needs to be mentioned. it is not column b and c then d and e, the equation reflects the columns the times are in. they are in C and D then there is the same equation for E and F.