calculate number of weeks in a given year

Question

I would like to get the number of weeks in any given year. Even though 52 is accepted as a generalised worldwide answer, the calendars for 2015,

Answer 1

For ISO date format, we can calculate number of weeks as follows:

int getNoOfWeeks(int year) {
    Calendar cal = Calendar.getInstance();
    cal.set(Calendar.YEAR, year);
    cal.setMinimalDaysInFirstWeek(4);
    cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
    return cal.getActualMaximum(Calendar.WEEK_OF_YEAR);
}

So, for year = 2018, it will return 52, for 2019, it will also return 52, but for 2020 it will return 53 as ISO year has 52 or 53 weeks.