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

Answer 1

java.time.YearMonth

How to Get First Date and Last Date For Specific Year and Month.

Here is code using YearMonth Class.

YearMonth is a final class in java.time package, introduced in Java 8.

public static void main(String[] args) {

    int year = 2021;  // you can pass any value of year Like 2020,2021...
    int month = 6;   // you can pass any value of month Like 1,2,3...
    YearMonth yearMonth = YearMonth.of( year, month );  
    LocalDate firstOfMonth = yearMonth.atDay( 1 );
    LocalDate lastOfMonth = yearMonth.atEndOfMonth();

    System.out.println(firstOfMonth);
    System.out.println(lastOfMonth);
}

See this code run live at IdeOne.com.

2021-06-01

2021-06-30

Answer 2

Calendar cal = Calendar.getInstance();//getting the instance of the Calendar using the factory method
we have a get() method to get the specified field of the calendar i.e year

int year=cal.get(Calendar.YEAR);//for example we get 2013 here 

cal.set(year, 0, 1); setting the date using the set method that all parameters like year ,month and day
Here we have given the month as 0 i.e Jan as the month start 0 - 11 and day as 1 as the days starts from 1 to30.

Date firstdate=cal.getTime();//here we will get the first day of the year

cal.set(year,11,31);//same way as the above we set the end date of the year

Date lastdate=cal.getTime();//here we will get the last day of the year

System.out.print("the firstdate and lastdate here\n");

Answer 3

You can use Jodatime as shown in this thread Java Joda Time - Implement a Date range iterator

Also, you can use gregorian calendar and move one day at a time, as shown here. I need a cycle which iterates through dates interval

PS. Piece of advice: search it first.

Answer 4

GregorianCalendar gcal = new GregorianCalendar();
gcal.setTime(start);
while (gcal.getTime().before(end)) {
    gcal.add(Calendar.DAY_OF_YEAR, 1);
    //Do Something ...
}

The GregorianCalendar creation here is pointless. In fact, going through Calendar.java source code shows that Calendar.getInstance() already gives a GregorianCalendar instance.

Regards, Nicolas

Answer 5

If you are looking for a one-line-expression, I usually use this:

new SimpleDateFormat("yyyy-MM-dd").parse(String.valueOf(new java.util.Date().getYear())+"-01-01")

Answer 6

You can use the apache commons-lang project which has a DateUtils class.

They provide an iterator which you can give the Date object.

But I highly suggest using the Calendar class as suggested by the other answers.