Trouble with duration portion of DATEADD function

[Dean_Arnold]

Hi there,

I’m trying to use the DATEADD function to calculate an end time for an event.

My formula is:
DATEADD({Timeslot StartTime},{Duration mins},‘minutes’)

{Duration mins} can be a lookup field or a formula field. I’ve tried all formatting options for these fields but none are producing the correct output.

If I make {Duration mins} a text field, the output is correct.

I need to make the formula work with {Duration mins} being either a lookup field or a formula ~ What am I doing wrong?

P.S. I have also tried to troubleshoot the issue by toggling the GMT settings on and off, all to no avail.

Thanks for your help.

[Dean_Arnold · Accepted solution]

Thanks for following up!

Peter from Airtable support found an alternate solution:

DATEADD({Timeslot StartTime},ARRAYJOIN({Duration mins}),‘minutes’)

Here is his fully reply:

"I believe I’ve fixed the issue by “wrapping” the reference to the lookup field with an ARRAYJOIN() fuction, which converts the Lookup field from an array to a string (which in turn makes it interpretable by the DATEADD() function).

Totally get that this is not intuitive – I actually raised this very same issue to our product team a few weeks back, and am going to use your message as an opportunity to do so again."

[Justin_Barrett]

Thanks for sharing what you got from Peter. Another function (that totally slipped my mind) that’s a little more intuitive is the SUM() function. Normally it’s used to add a collection of values, but it works just as well when passed a single value in an array.

DATEADD({Timeslot StartTime}, SUM({Duration mins}), 'minutes')