Calculation with Dates - Strange Behaviour?

I have the following formula in my Due Date column:

=IF(ISBLANK([Invoice Sent Date]@row), "Invoice not sent", [Invoice Sent Date]@row + [Payment Term (days)]@row)

And when I test with the value 15 in the Payment Term (days) I get this really odd result, adding 15 to the year value... in fact not even adding but replacing what is the year 2020 into the year 2015 ?!

It's even more odd because all I am trying to do really is what is described in this article ( but instead of using hardwired values I use the value from another column.

What am I missing?

Best Answer


Help Article Resources

Want to practice working with formulas directly in Smartsheet?

Check out the Formula Handbook template!