How to calculate week number?

[Ryball]

Im creating a small booking app, where the users are used to Weeknumbers.

Is it posible to spesify like :

Week : 5  

Result would be : 30/1-2017 - 5/2-2017

Or vice versa,

Spesify the date and then get the current weeknumber.

This allso has to adjust for leap year.

Best Regards

Raymond

[Mike8]

Thank you @Anonymous,

I was looking for this. I will try it tomorrow 🙂

[AUPowerappps]

hello,

i am french,i need a formula to calculate week number calendar European.

Best regards,

Audric.

[The_Hawk]

Thank you dionmills_argos it helped a lot !

[datamaster]

This worked great after I replaced all the ";" and replaced them with ",". Also I replace the datapicker with today() to get today's weeknumber.

[Anonymous]

I've attached my solution for calculating the week number based off of Today().  All the examples looked like fun so I wanted to try my hand as well.  Only minor testing performed but it seems to work.  How it works is:

- Find the number of days between the current date and the first of the year using DateDiff

- Add the day of the week for the first of the year using "WeekDay"

- Divide by 7

- Round Up

RoundUp((DateDiff(DateValue(Concatenate("1/1/", Text(Year(Today())))), Today()) + Value(WeekDay(Concatenate("1/1/", Text(Year(Today())))))))/7,0)

[Mike8]

Hello DennisO,

Thank you for sharing.
I copy paste the expression but I receive an error. Are you sure it works? Can you copy paste what you have posted and try it, please?

[AUPowerappps · Accepted solution]

Weekk number ISO:

RoundDown((RoundUp(selec.SelectedDate-Date(Year(selec.SelectedDate-Weekday(selec.SelectedDate-1)+4);1;3);0)+
Weekday(Date(Year(selec.SelectedDate-Weekday(selec.SelectedDate-1)+4);1;3))+5)
/7;0)

selec=datepicker or label

Spoiler

remove ;  /  , if need

[The_Hawk]

Hi AUPowerapps,

It works perfectly ! Thank you !

[ShivamJindal]

I am trying to use this formula with a date picker and 1,1 as suggested by you and getting a -ve week value. . . For the first week on tear it is ok. . And in the second week it says "0" and after that -ve. can you please help.

[venseben]

This solution rocks. THX a 1000 times @AUPowerappps 

Frank

Denmark