Date Class in Java

java.util.Date Class in Java

Last Updated: 06 March, 2023

The class Date represents a specific instant in time with millisecond precision. The Date class was introduced in the JDK 1.0 release and is available in the java.util package.

The java.util.Date class provides many constructors and methods to deal with date and time in Java.

Date Class declaration:

 public class Date extends Object implements Serializable, Cloneable, Comparable<Date>

The java.util.Date class extends Object class and implements the Serializable, Cloneable, and Comparable interfaces.

The java.util.Date class is inherited by java.sql.Date, java.sql.Time and java.sql.Timestamp interfaces in Java.

java.util.Date Class Constructors

No.	Constructor with Description
1.	Date() It creates a Date object that represents the current date and time.
2.	Date(long milliseconds) It creates a date object for the given milliseconds since January 1, 1970, 00:00:00 GMT.
3.	Date(int year, int month, int date) Depricated It creates a date object with the specified year, month, and date.
4.	Date(int year, int month, int date, int hrs, int min) Depricated It creates a date object with the specified year, month, date, hours, and minuts.
5.	Date(int year, int month, int date, int hrs, int min, int sec) Depricated It creates a date object with the specified year, month, date, hours, minuts, and seconds.
6.	Date(String s) Depricated It creates a Date object and initializes it so that it represents the date and time indicated by the string s, which is interpreted as if by the parse(java.lang.String) method.

No.

Constructor with Description

Date()

It creates a Date object that represents the current date and time.

Date(long milliseconds)

It creates a date object for the given milliseconds since January 1, 1970, 00:00:00 GMT.

Date(int year, int month, int date) Depricated

It creates a date object with the specified year, month, and date.

Date(int year, int month, int date, int hrs, int min) Depricated

It creates a date object with the specified year, month, date, hours, and minuts.

Date(int year, int month, int date, int hrs, int min, int sec) Depricated

It creates a date object with the specified year, month, date, hours, minuts, and seconds.

Date(String s) Depricated

It creates a Date object and initializes it so that it represents the date and time indicated by the string s, which is interpreted as if by the parse(java.lang.String) method.

  
  import java.util.Date;
  public class DateExample {
    public static void main(String[] args) {
      // Date class default constructor
      Date date1 = new Date();
      System.out.println("Current Date & Time: " + date1);
      
      // Date class parameterized constructor, pass long value as a milliseconds
      Date date2 = new Date(2123121232L);
      System.out.println("Date represented is " + date2);
    }
  }

Current Date & Time: Sat Mar 04 12:21:48 IST 2023
Date represented is Sun Jan 25 19:15:21 IST 1970

java.util.Date Class Methods

No.	Methods with Description
1.	long getTime() It returns the time represented by this date object.
2.	boolean after(Date date) It returns true if the invocation date is after the argumented date.
3.	boolean before(Date date) It returns true if the invocation date is before the argument date.
4.	Date from(Instant instant) It returns an instance of the Date object from an instant date.
5.	void setTime(long time) It changes the current date and time to the given time.
6.	Object clone( ) It duplicates the invoking Date object.
7.	int compareTo(Date date) It compares the current date with the given date.
8.	boolean equals(Date date) It compares the current date with the given date for equality.
9.	int hashCode() It returns the hash code value of the invoking date object.
10.	Instant toInstant() It converts the current date into an instant object.
11.	String toString() It converts this date into an instant object.

No.

Methods with Description

long getTime()

It returns the time represented by this date object.

boolean after(Date date)

It returns true if the invocation date is after the argumented date.

boolean before(Date date)

It returns true if the invocation date is before the argument date.

Date from(Instant instant)

It returns an instance of the Date object from an instant date.

void setTime(long time)

It changes the current date and time to the given time.

Object clone( )

It duplicates the invoking Date object.

int compareTo(Date date)

It compares the current date with the given date.

boolean equals(Date date)

It compares the current date with the given date for equality.

int hashCode()

It returns the hash code value of the invoking date object.

10.

Instant toInstant()

It converts the current date into an instant object.

11.

String toString()

It converts this date into an instant object.

  
  import java.util.Date;
  public class DateExample {
    public static void main(String[] args) {
      Date date1 = new Date(2005, 8, 26);
      Date date2 = new Date();
      Date date3 = new Date(2022, 4, 16);
      
      // Tests if this date is after the specified date.
      boolean a = date3.after(date1);
      System.out.println("Date date3 comes after " + "date date2: " + a);
      
      // Tests if this date is before the specified date.
      boolean b = date3.before(date2);
      System.out.println("Date date3 comes before " + "date date2: " + b);
      
      // Compares two Dates for ordering.
      int c = date1.compareTo(date2);
      System.out.println(c);
      
      // Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT
      System.out.println("Miliseconds from Jan 1 " + "1970 to date date1 is: " + date1.getTime());
      
      System.out.println("Before setting: "+date2);
      // Sets this Date object to represent a point in time that is time milliseconds after January 1, 1970 00:00:00 GMT.
      date2.setTime(204587433443L);
      System.out.println("After setting: "+date2);
      
      // Use of clone() method
      Object date4 = date1.clone();
      System.out.println("Cloned date4: " + date4.toString());
      
      // Use of equals() method
      System.out.println("date1.equals(date4): " + date1.equals(date4));
      System.out.println("date1.equals(date2): " + date1.equals(date2));
    }
  }

Date date3 comes after date date2: true
Date date3 comes before date date2: false
1
Miliseconds from Jan 1 1970 to date date1 is: 61085817000000
Before setting: Sat Mar 04 12:49:10 IST 2023
After setting: Sat Jun 26 03:20:33 IST 1976
Cloned date4: Tue Sep 26 00:00:00 IST 3905
date1.equals(date4): true
date1.equals(date2): false

About java.sql.Date Class

In Java, there is another Date class that is available in the java.sql package. The java.sql.Date class extends the java.util.Date class.

The java.sql.Date is used to represent SQL DATE, which keeps years, months, and days. No timing data is kept.

The java.sql.Date class should only be used while dealing with databases, and it does not hold information about the time zone.

java.util.Date Class in Java

java.util.Date Class Constructors

java.util.Date Class Methods

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