Hey all! I have recently started using Airtable and I have been searching for an answer to this question for too long.

I am attempting to track volunteer hours. I have a form that people will complete every time they have a “shift”. This form asks people when they came in and when they left. I want to create a formula that finds the difference of the End time and the Start time in order to find the total time of their shift.

I have read through several ask the community questions similar to this and tried several formulas; including DATETIME_DIFF. However, nothing seems to be working.

Please help! Thanks in advance.

# Calculating the difference in time between two date fields

I am at the point of almost leaving a question in the form that asks for the volunteer to put the duration of their shift. However, I would much rather have airtable do so automatically.

You just need to use commas to separate the parameters you pass into the DATETIME_DIFF() function:

```
DATETIME_DIFF(
{End Time},
{Start Time},
'hours'
)
```

I had used this formula: And it seemed to be working fine, but now it’s giving me negative results.

So I tried the ‘hours’ * 60 and it gave me an error. Any clue what am I doing wrong?

Yes, **you have those Starts after the corresponding Ends**, instead of before (they maybe are swapped).

What I meant with ‘hours * 60’ was that, if you expect for instance to get a `6`

because your want to get hours, when you specify minutes, **the number should be 360, what is 6 multiplied by 60**.

SO swapping just swapped which records came out positive/negative. 60 & 360 both gave me errors.

Okay I didn’t realize ‘*360’ had to be written with a comma. So I put the comma & the negatives do not change…

your last post with pictures looks like it did everything correctly, the clock out times were just entered incorrectly(before start time) so you [correctly] got negative numbers.

I just realized that was the issue. Thank you so much for being so responsive!

This was not clear?

No, `DATETIME_DIFF`

expect just a unit as the third parameter, you can’t put something like ‘hours * 3600’. Again, it was just **a way of explaining that whichever unit you used (hours or minutes), you should get a correct number**, and not a `-0`

.

- If you expect to get 5 hours but you specify
`minutes`

as the unit, you’ll get`300`

, because 5 hours has 300 minutes. - If you expect to get 90 minutes but you specify
`hours`

as the unit, you’ll get`1.5`

, because 90 minutes are equal one and a half hour

I can’t believe I am explaining this