Why Does DATETIME_DIFF Show the Wrong Value in Airtable Even When the Preview Looks Correct?

Let’s say you’re tracking the duration between a Start Time and an End Time in Airtable

You add a formula field and use the following formula

DATETIME_DIFF({End Time}, {Start Time}, "minutes")

In the preview, Airtable shows a sample value of 120, which is exactly what you expect for a two-hour difference

But when you look at the actual field in your table, it shows 0:02

Why is that happening?

By default, a formula field formatted as Duration is set to h:mm

In h:mm format, Airtable interprets the number as seconds, not minutes. So 120 seconds becomes 0:02, meaning 0 hours and 2 minutes

If you switch the formatting to h:mm:ss, it will show 2:00:00 for a two-hour duration, which correctly represents hours and minutes

Airtable is not doing the math wrong; it is just displaying the result differently based on the field’s formatting

The Solution

If you want to see 120 instead of 0:02, you need to tell Airtable to treat the result as a number

Go to the Formatting tab of the field settings and change the Format from Duration to Number