Weeks In Year (ISO)
Gets the number of weeks in the current year, according to ISO weeks.
This requires the
IsoWeeksInYear
plugin to work
dayjs.extend(isoWeeksInYear)
dayjs.extend(isLeapYear)
dayjs('2004-01-01').isoWeeksInYear() // 53
dayjs('2005-01-01').isoWeeksInYear() // 52