Calculating week-of-year for a date

[aurdipas]

Hi @Xiphware, I didn't talk of Aggregate. Try to upload your xls on http://opendatakit.org/xlsform/ and you'll see what I mean.
I opened a post on support on the issue:

Validate issue for decimal-date-time

What is the problem? Please be detailed. This post is linked to the form on the Showcase channel If I convert the form with XLSForm (online/offline) it gives a validation error. The sysntax looks correct and if I use the offline converter without validation, it converts the form that works correctly in Collect. What breaks the validator is the calculation decimal-date-time(concat(${year}, "-01-01")) where ${year} is the year extracted from a date. Another issue is that because there's a…