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

[GregLi · Accepted solution]

Excel compatible WeekNum and ISOWeekNum functions have been added to Power Fx and Canvas apps in version 3.21081.