# Formula for adding months onto a date

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edited 09/08/21

Hi!

Can someone please help me with a formula to auto calculate the 'Expected Finish' by adding the 'Duration' to 'Actual / Expected Start Date'?

Thanks so much!

This formula is getting an 'invalid data type' error:

=IF((MONTH([Actual / Expected Start Date]@row) + VALUE(LEFT(Duration@row, FIND(" ", Duration@row) - 1))) > 12, DATE(YEAR([Actual / Expected Start Date]@row) + 1, MOD(MONTH([Actual / Expected Start Date]@row) + VALUE(LEFT(Duration@row, FIND(" ", Duration@row) - 1)), 12), DAY([Actual / Expected Start Date]@row)), DATE(YEAR([Actual / Expected Start Date]@row), MONTH([Actual / Expected Start Date]@row) + VALUE(LEFT(Duration@row, FIND(" ", Duration@row) - 1)), DAY([Actual / Expected Start Date]@row)))

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This Formula is leaving an 'INVALID DATA TYPE' error:

=IF((MONTH([Actual / Expected Start Date]@row) + VALUE(LEFT(Duration@row, FIND(" ", Duration@row) - 1))) > 12, DATE(YEAR([Actual / Expected Start Date]@row) + 1, MOD(MONTH([Actual / Expected Start Date]@row) + VALUE(LEFT(Duration@row, FIND(" ", Duration@row) - 1)), 12), DAY([Actual / Expected Start Date]@row)), DATE(YEAR([Actual / Expected Start Date]@row), MONTH([Actual / Expected Start Date]@row) + VALUE(LEFT(Duration@row, FIND(" ", Duration@row) - 1)), DAY([Actual / Expected Start Date]@row)))

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I will dig through my notes and get back to you, but you should be able to find something that you can adapt if you search for "EDATE" here in the Community. There are a few posts floating around where we have built out solutions for adding a variable number of months to a date.

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Try taking a look through this thread...

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