WEEKNUMBER formula not returning correct result

AFlint

When I use the formula for WEEKNUMBER, my results are being offset by 1 week between Sunday and Monday.

Sunday, Sept. 12 = Week 36 (Correct)

Monday, Sept 13 = Week 37 (Incorrect)

I have checked my project settings, set my working days, etc., but I cannot figure out why this formula will not return the correct week number for Monday.

Can anyone give an advice? Thank you

Matthew Emrich

I think Smartsheet calculates weeks Monday to Sunday. I would suggest using an If function to solve this

ex: =IF([Day of the Week]@row = "Sunday", WEEKNUMBER(Date@row) + 1, WEEKNUMBER(Date@row))

AFlint

Your formula suggestion made me do some digging. Apparently, SS uses ISO Week Dates (link: https://en.wikipedia.org/wiki/ISO_week_date)

Seemingly, it is not an error, but a different way of tracking dates. I'll just need to adjust my timeline to accomodate.

Thanks for trying to help.