While troubleshooting an issue with WEEKNUM(), I came across a curious fact that I thought I would share.

The internet, or at least the websites youâ€™d go to for answers if you Googled something, donâ€™t count the first incomplete week of the year when figuring week numbers.

Which means if youâ€™re in the US (among a few other countries) and searched the internet to find out what week number it wasâ€¦
 the numbers would be wrong (from your perspective).

Which means if youâ€™re in the US (among a few other countries) and searched the internet to find out what week number it wasâ€¦
Assume that for this discussion, Sunday is the start of the week
 Letâ€™s work with the date: Sunday July 11th, 2021
In Google Sheets & AppSheet
 WEEKNUM(â€ś7/11/2021â€ť) = 29
 If you physically count the number of weeks on a calendar, youâ€™ll get 29 too.
 IF you count the first incomplete week, that isâ€¦
But On The Internet
 WEEKNUM(â€ś7/11/2021â€ť) = 28
It seems that the internet doesnâ€™t count the first incomplete week of the year
Every webpage that Iâ€™ve gone to tells me that the week number for July 11th, 2021 is 28.
Check for yourself:
Examples
Some Results:
 Week Numbers for 2021
 This one starts the week on Monday, but still you see the next week is 28  not 29.
 https://weeknumber.com/
 Another that starts itâ€™s weeks on Monday  but still, the next week should be 29, not 28.
Thatâ€™s 4 websites that Iâ€™ve given pictures from, but every website on the first two pages of results for that search give this answer
I donâ€™t know about you, but I had no idea that this wasnâ€™t a standardacrosstheworld thing.
Iâ€™m curious what everyone thinks?
 When should we start counting the first week of the year?
 Start counting from the first FULL week
 Start counting from the first DAY
0 voters