How to get the first date and last date of current quarter in java.util.Date

Question

I need to get the first date of the current quarter as a java.util.Date object and the last date of the current quarter as a java.util.Date

Answer 1

private static Date getFirstDayOfQuarter(Date date) {
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    cal.set(Calendar.DAY_OF_MONTH, 1);
    cal.set(Calendar.MONTH, cal.get(Calendar.MONTH)/3 * 3);
    return cal.getTime();
}

private static Date getLastDayOfQuarter(Date date) {
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    cal.set(Calendar.DAY_OF_MONTH, 1);
    cal.set(Calendar.MONTH, cal.get(Calendar.MONTH)/3 * 3 + 2);
    cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));
    return cal.getTime();
}

This should work, but I suggest you to test it more carefully than I did. Note: Division of int values in Java returns the floor value.

Answer 2

It's pretty simple with LocalDate

LocalDate inputDate = LocalDate.parse("2018-09-04");
LocalDate firstDayOfQuarter = inputDate.withMonth(inputDate.get(IsoFields.QUARTER_OF_YEAR) * 3 - 2).with(TemporalAdjusters.firstDayOfMonth());
LocalDate lastDayOfQuarter = inputDate.withMonth(inputDate.get(IsoFields.QUARTER_OF_YEAR) * 3).with(TemporalAdjusters.lastDayOfMonth());

Cheers!