How to display -/+ variences with time?

[CP4840]

I have having an issue with calculating the difference between two times when there is a negative. I am trying to put together a departure schedule. If the scheduled departure time is 23:15 and the truck does not depart until 00:01 then the variance is 00:46. That means the truck left 46mins late. I figured out that formula. Now, if the truck leaves at 23:00 I get a calculation of 23:45, when I need it to display that the truck was early by 15 mins or -00:15.

d= the constant or the scheduled depart time (23:15)
e= the actual depart time (23:00)
f= the formula I am currently using is =E19-D19+IF(D19>E19,1)

I would really appreciate any help; maybe there is an easier way to do this?

 

[barry houdini]

This is tricky when you are using times and no dates but one way would be to use this formula

=IF((E19-D19+(D19>E19))<0.5,TEXT(1+E19-D19,"hh:mm"),"-"&TEXT(ABS(E19-D19),"hh:mm"))

or perhaps..

=TEXT(1440*(((E19-D19+(D19>=E19))<0.5)+E19-D19),"0")& " mins late"

 

[Yogi Anand]

Edit: looks like mine might turn out to be what barry has already posted!

Hi CP4840:

How about ...

Book1
	D	E	F	G
18	Schedudled	Actual	LateByMinutes
19	23:15	0:01	00:46
20	23:15	23:00	-00:15
Sheet5

formula in cell F19 is ...

=IF((E19-D19+(E19<D19))>0.5,"-"&TEXT(ABS(E19-D19),"hh:mm"),TEXT(E19+1-D19,"hh:mm"))

 

[CP4840]

Guys,
Thank you sensei, you are both bona fide wise man. Seriously, thanks for the help with the formula, it worked perfect.