Cldr.Calendar.Julian.week_of_year

You're seeing just the function week_of_year, go back to Cldr.Calendar.Julian module for more information.

week_of_year(year, month, day)

week_of_year(year(), month(), day()) :: {:error, :not_defined}

Calculates the week of the year from the given year, month, and day. It is an integer from 1 to 53.