# Calculate time by adding hours and minutes

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I want to create an agenda with start times. I want to specify the start time for the fist item and then have Smartsheet calculate the start times of the remaining items based on how many minutes are assigned to the previous item. Any ideas how to do this?

In excel, I’m able to use 0:00:00 AM/PM format and SUM them.

I’m struggling with this in smartsheet.

Thanks.

## Answers

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Hi Andrew

Thank you for taking the time to answer this question! The formula worked for the first 2 cells and then it broke because I need to figure out how to add a "duration column" to my smartsheet. I realize if I had started it as a "project", that column would already be there but I did not. :(

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Thank you @Andrew Stewart !

Your solution worked perfectly.

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The formula stops working correctly between 10:25 and 10:35. See my example. The bottom start time should be 10:35. Here is my formula on the "11:25" result:

=ROUND(Minutes@row / 60) + ":" + RIGHT("0" + (Minutes@row - 60 * ROUND(Minutes@row / 60)), 2)

Or, time goes backwards. Here are rows 10 and 11. My minutes formula in row 11 is =Minutes10 + [Minutes in Current Agenda]10 but I get a start time of 13:15 instead of 13:35.

And just one last anomaly... some of the times have a "-" in the minutes. This is the formula:

=ROUND(Minutes@row / 60) + ":" + RIGHT("0" + (Minutes@row - 60 * ROUND(Minutes@row / 60)), 2)

Any thoughts?

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Wow! Thanks @A. Scott McCulloch ! That makes a lot of sense. I'll give it a try.

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I just got to try the ROUNDDOWN in my agenda and it totally worked! Thank you SO MUCH for posting that suggestion!

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