Find next quarter end date given previous quarter end date using Java

Loren :

I am having quarter end date of last quarter let it be 30-09-20 , the requirement is to find end date of next quarter i.e 31-12-20. I am using below code to do the same but is it giving wrong output in some scenarios. This solution should be correct for all quarters.

String str = "30-09-20";
SimpleDateFormat format = new SimpleDateFormat("dd-MM-yy");
Date date = format.parse(str);
Date newDate = DateUtils.addMonths(date, 3);
System.out.println(newDate);//Dec 30 - It should be 31 Dec

YCF_L :

To answer your question, I think you are looking for this :

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yy");
LocalDate end = LocalDate.parse("30-09-20", formatter)
    .plusMonths(3)                             // add three months to your date
    .with(TemporalAdjusters.lastDayOfMonth()); // with the last day of the month

Note: don't use the legacy Date library, you tagged your question Java-8 which mean you can use java-time API.

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Get last day of current quarter

@deHaar have reason, to get the end date of curent quarter, I would suggest to use :

public LocalDate lastDayFromDateQuarter(String date) {
    final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yy");
    LocalDate ld = LocalDate.parse(date, formatter);
    int quarter = ld.get(IsoFields.QUARTER_OF_YEAR); // Get the Quarter, 1, 2, 3, 4
    // Then create a new date with new quarter * 3 and last day of month
    return ld.withMonth(quarter * 3).with(TemporalAdjusters.lastDayOfMonth());
}

Get last day of next quarter

To get the last day of the next quarter, then you just can add three months to your date like so :

public static LocalDate lastDayFromDateQuarter(String date) {
    final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yy");
    LocalDate ld = LocalDate.parse(date, formatter);
    int quarter = ld.get(IsoFields.QUARTER_OF_YEAR);
    return ld.withMonth(quarter * 3)
            .plusMonths(3)
            .with(TemporalAdjusters.lastDayOfMonth());
}