Date Logic - Weekends versus duration


I'm hoping someone in the community can help me understand the business logic behind the way durations are calculated over weekends in Smartsheet.

For context, my sheet has out-of-box settings for working days and hours - Sat and Sun are non-working days, M-F are 8-hour durations.

Looking at the attached example, I think it's reasonable to expect that "Test I" has a 3-day duration, given that the first working day is a Friday, and the next two working days are teh following Monday and Tuesday. The Gantt reflects this, showing the bar stretch across three white (available) days on the grid.

Where I get lost is the following two lines. I would expect Test J to have and end date of Wednesday 2/20/19, given that the first working day is a Monday, and the duration is 3 days long. Instead, it ends on Tuesday, but the duration still reads 3 days long. The Gantt bar stretches over only two white (available) spaces on the grid.

Similar issue with Test K, since it starts on a Sunday. Shouldn't the three-day duration activity end on a Wednesday at the end of the day? Why does the system calculate Tuesday?

PS - My reason for nit-picking this stems from the fact that another system that we're integrating with Smartsheet calculates end dates differently, and we're seeing discrepancies when calculating our end dates, despite the fact that start dates and durations are coming through perfectly. In the other system, Test J and Test K both end on Wednesday, as expected.



  • Shaine Greenwood


    Some key behaviors to recognize here in the way Smartsheet calculates duration:

    1. Smartsheet will allow you to start a task on a nonworking day. (It pushes End Dates out to the next available working day.)
    2. The Start Date will always be counted, even if it starts on a nonworking day. 

    What's happening here is that Smartsheet is counting the Start Date and all working days involved to calculate the duration of these tasks.

    Hope that clears things up a bit. Let me know if you have any questions!

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