How to get start and end date of a year?

Question

I have to use the Java Date class for this problem (it interfaces with something out of my control).

How do I get the start and end date of a year and then iterate through each date?

Answer 1

java.time

Using java.time library built into Java 8 and later. Specifically the LocalDate and TemporalAdjusters classes.

import java.time.LocalDate import static java.time.temporal.TemporalAdjusters.firstDayOfYear import static java.time.temporal.TemporalAdjusters.lastDayOfYear  LocalDate now = LocalDate.now(); // 2015-11-23 LocalDate firstDay = now.with(firstDayOfYear()); // 2015-01-01 LocalDate lastDay = now.with(lastDayOfYear()); // 2015-12-31 

If you need to add time information, you may use any available LocalDate to LocalDateTime conversion like

lastDay.atStartOfDay(); // 2015-12-31T00:00 

Answer 2

Calendar cal = Calendar.getInstance(); cal.set(Calendar.YEAR, 2014); cal.set(Calendar.DAY_OF_YEAR, 1);     Date start = cal.getTime();  //set date to last day of 2014 cal.set(Calendar.YEAR, 2014); cal.set(Calendar.MONTH, 11); // 11 = december cal.set(Calendar.DAY_OF_MONTH, 31); // new years eve  Date end = cal.getTime();  //Iterate through the two dates  GregorianCalendar gcal = new GregorianCalendar(); gcal.setTime(start); while (gcal.getTime().before(end)) {     gcal.add(Calendar.DAY_OF_YEAR, 1);     //Do Something ... }