# Calculate days difference between 2 dates but same completion date

Hello to the community, this is my first post! Apologies in advance for any poor description, I’m weak in formulas!
I would like to ask for your advice on how to approach a problem:

1 have 1 Date column and 1 Timeline column. We also have a Completion Date.

What I want to calculate is this:
The difference between (Date vs Completion Date) - (Timeline#End vs Completion Date)

Example:
I have set a Date for a construction.
A contractor sets a Timeline for the same task
I calculate the amount of days passed from my Date till completion
I calculate the amount of days passed from contractor’s Timeline#End till completion.
If there’s a +days difference I need to charge them extra
If there’s a 0days difference all good
If there’s a -days difference they get a bonus.

Is that possible to be translated in a formula?
I hope that makes sense!
Greetings from Greece,
Stelios

Use the DAYS function. It gives you the number of days between the 2 dates.

DAYS({Date},{CompletionDate})

So in the end it should look like this:

IF(DAYS({Date},{Timeline#End}) = DAYS({Date},{Completion Date}), "OK" ,
IF(DAYS({Date},{Timeline#End}) > DAYS({Date},{Completion Date}), "Charge", "Bonus")
)
1 Like

I will give this a try, thank you so much!!