Returns the week in a month of a date as a number. If no argument is given, then the current local date/time, as returned by date:date-time is used as the default argument.
week-in-month($date-time as string?) ➔ number
The input date/time
Links to specifications
For the purposes of numbering, the first day of the month is in week 1 and new weeks begin on a Monday (so the first and last weeks in a month will often have less than 7 days in them).