Calculating duration for a min time and a max time

[Spikenaylor]

I have items going into a fridge
the first item goes in and the temp and humidty of the fridge goes out and comes back in at some point, same with the other items.

The time the fridge comes back into spec after all items are placed into the fridge is the time used as the earliest that the last item can come out in 69 hours

The first item placed in the fridge has an amended time due to fridge going in and out of spec.
this amended time is the time used for the latest time the first item can be removed from the fridge in 75 hours.


for my calculations:

I have a start date and time

01-07-18 12:15

I have an amended start time

01-07-18 10:54

my minimum duration is the start date and time + 69 hrs
my maximum duration is the amended start date and time +75 hrs

so:
my earliest removal time is 04-7-18 09:15
my latest time is 04-07-18 13:54

my actual date and time of removal is

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04-07-18 09:15

this should give a duration of 69:00

change the actual removal to
04-07-18 13:54
this should give a duration of 75:00

I cant get the formula to use the amended time as well as the earliest time to give me the correct result
the problem being is I have two effective start times

any help or guidance much appreciated

Date	Fridge reached spec after last item entered	amended time for first item entered into fridge due to out of spec	Earliest date and time final item can be removed (+69 hrs)	Latest date and time first item can be removed (+75 hrs)	Date and time of removal of all items	Duration
01-07-18	12:15	10:54	04-07-18 09:15 ((A2+B2)+69hrs)	04-07-18 13:54 ((A2+C2)+75hrs)	04-07-18 09:15	=F2-?
						If removed at 09:15 then duration is 69hrs
						If removed at 13:54 then the duration is 75hrs

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