How to get UTC time in Java?

In Java, we often need to convert a time of one timezone into another timezone. UTC stands for Universal Time Coordinated (UTC). Before commence of UTC it was called Greenwich Mean Time (GMT). Indian users need to convert the IST time into UTC time when working in different time zones.

In Java, there are many ways to get UTC time which are given below:

1. Current UTC Time - SimpleDateFormat

SimpleDateFormat is one of the most important classes which plays an important role in getting UTC time. SimpleDateFormat is mainly used in the older version of Java, such as Java8.

Let's take an example to understand how we can get UTC time by SimpleDateFormat in Java8.

UTCTimeExample1.java

// import required classes and packages
package javaTpoint.JavaExample;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
import japa.parser.ParseException;

// create class UTCTimeExample1 to get the current UTC time by using SimpleDateFormat
public class UTCTimeExample1 {
	
	// main() method start
	public static void main(String args[])
	{
		// use try-catch block to execute the code or catch the exception
		try {
			// print current time zone 
			System.out.println("IST Time is:"+new Date());
			System.out.println("UTC Time is: "+getCurrentUtcTime());
		} 
		// for handling parsing errors and exceptions
		catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	// create getCurrentUtcTime() method to get the current UTC time
	public static Date getCurrentUtcTime() throws ParseException {	// handling ParseException
		// create an instance of the SimpleDateFormat class
	    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
	    // set UTC time zone by using SimpleDateFormat class
	    sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
	    //create another instance of the SimpleDateFormat class for local date format
	    SimpleDateFormat ldf = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
	    // declare and initialize a date variable which we return to the main method
	    Date d1 = null;
	    // use try catch block to parse date in UTC time zone
	    try {
	    	// parsing date using SimpleDateFormat class
			d1 = ldf.parse( sdf.format(new Date()) );
		} 
	    // catch block for handling ParseException
	    catch (java.text.ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			System.out.println(e.getMessage());
		}
	    // pass UTC date to main method.
	    return d1;
	}
}

Output:

2. Current UTC Time - Java 8 Instant

In Java8, we can easily get the current UTC time by creating an instance of the Instant object. Java8 brought an excellent new Java.time.* package for using the old java Date/Calendar classes. The Instant class defines a moment of the timeline in UTC as the default time zone.

Let's take an example to understand how we can get current UTC time by using Java8 Instant:

UTCTimeExample2.java

// import required classes and packages
package javaTpoint.JavaExample;

import java.time.Instant;
import java.util.Date;
// create class UTCTimeExample2 to get the current UTC time by using Java8 Instant class
public class UTCTimeExample2 {
	// main() method start
	public static void main(String[] args)
	{
		// print current time
		System.out.println("IST Time is:"+new Date());
		// print current UTC time
		System.out.println("UTC Time is: "+getCurrentUtcTime());
	}
	// create getCurrentUtcTime() method to get the current UTC time
	public static String getCurrentUtcTime() {
		// declare and initialize a date variable which we return to the main method
		String d1;
		// create an instance of Instant class for getting current UTC time
		Instant instant = Instant.now();
		// use toString() method to convert instant object into String
		d1 = instant.toString();
	    // pass UTC date to main method.
	    return d1;
	}
}

Output:

3. Current UTC Time - Java8 OffsetDateTime

Java OffsetDateTime class is one of the important class to get current UTC time. OffsetDateTime is an immutable representation of a date-time with an offset that is mainly used for storing date-time fields into the precision of nanoseconds.

Let's take an example to understand how we can get current UTC time by using OffsetDateTime class:

UTCTimeExample3.java

import java.time.OffsetDateTime;
import java.time.ZoneOffset;
import java.util.Date;
// create class UTCTimeExample3 to get the current UTC time by using Java8 OffsetDateTime class
public class UTCTimeExample3 {	
	// main() method start
	public static void main(String args[])
	{
		// print current time
		System.out.println("IST Time is:"+new Date());
		// print current UTC time
		System.out.println("UTC Time is: "+getCurrentUtcTime());
	}
	// create getCurrentUtcTime() method to get the current UTC time
	public static OffsetDateTime getCurrentUtcTime() {		
		// declare and initialize an OffsetDateTime variable which we return to the main method
		OffsetDateTime d1;
		// initialize d1 by using now() method of OffsetDateTime
		d1 = OffsetDateTime.now(ZoneOffset.UTC);
		// pass UTC date to the main method.
	    return d1;
	}
}

Output:

4. Current UTC Time - Joda Time

Java Joda Time API is an important API that can also be used to get the current UTC time. In order to use Joda Time, we need to add the following dependency in our POM.xml file:

<dependency>
<groupId>joda-time</groupId>
<artifactId>joda-time</artifactId>
<version>2.10.2</version>
</dependency>

Let's take an example to understand how we can get current UTC time by usingJoda Time API:

UTCTimeExample4.java

// import required classes and packages
import java.util.Date;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
// create class UTCTimeExample4 to get the current UTC time by using JODA API
public class UTCTimeExample4 {
	// main() method start
	public static void main(String[] args)
	{
		// print current time
		System.out.println("IST Time is:"+new Date());
		// print current UTC time
		System.out.println("UTC Time is: "+getCurrentUtcTime());
	}
	// create getCurrentUtcTime() method to get the current UTC time
	public static DateTime getCurrentUtcTime() {
		// declare and initialize a DateTime variable which we return to the main method
		DateTime d1;		
		// get default time zone
		DateTime now = new DateTime();
		// converting default zone to UTC
	    d1 = now.toDateTime(DateTimeZone.UTC ); 
		// pass UTC date to the main method.
	    return d1;
	}
}

Output:

All the above-discussed methods are used to get the current UTC time in Java, and we mostly use SimpleDateFormat class for getting UTC time.

Let's take one more example to understand how we can convert the given time into UTC time.

UTCTimeExample5.java

//import required classes and packages
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.Scanner;
//create UTCTimeExample5 class to convert given time into UTC time
public class UTCTimeExample5 {	
	// main() method start
	public static void main(String[] args)
	{
		// declare variable for initialize LocaleDateTime
		int hour1, hour2, min1, min2, sec1, sec2, yr1, yr2, month1, month2, day1, day2;
		LocalDateTime date1, date2;
		// create Scanner class object to take input from the user for initializing LocaleDateTime
		Scanner sc = new Scanner(System.in);
		// get input from used for initializing date1
		System.out.println("Enter Datetime for initializing the first LocaleDateTime object:");
		System.out.println("Enter year:");
		yr1 = sc.nextInt();
		System.out.println("Enter month:");
		month1 = sc.nextInt();
		System.out.println("Enter day:");
		day1 = sc.nextInt();
		System.out.println("Enter hours:");
		hour1 = sc.nextInt();
		System.out.println("Enter minutes:");
		min1 = sc.nextInt();
		System.out.println("Enter seconds:");
		sec1 = sc.nextInt();
		// initialize LocaleDateTime object for date1
		date1 = LocalDateTime.of(yr1, month1, day1, hour1, min1, sec1);
		System.out.println("Date1: " + date1);
		// print UTC time return by getCurrentUtcTime() method
		System.out.println("UTC Time: "+getCurrentUtcTime(date1));
		// get input from used for initializing time2
		System.out.println("Enter Datetime for initializing the second LocaleDateTime object:");
		System.out.println("Enter year:");
		yr2 = sc.nextInt();
		System.out.println("Enter month:");
		month2 = sc.nextInt();
		System.out.println("Enter day:");
		day2 = sc.nextInt();
		System.out.println("Enter hours:");
		hour2 = sc.nextInt();
		System.out.println("Enter minutes:");
		min2 = sc.nextInt();
		System.out.println("Enter seconds:");
		sec2 = sc.nextInt();
		// close scanner class object
		sc.close();
		// initialize LocalTime object for date2
		date2 = LocalDateTime.of(yr2, month2, day2, hour2, min2, sec2);
		System.out.println("Date2: " + date2);
		// print UTC time return by getCurrentUtcTime() method
		System.out.println("UTC Time:"+getCurrentUtcTime(date2));
	}
	// create getCurrentUtcTime() method to convert given LocalDatetime into UTC time
	public static LocalTime getCurrentUtcTime(LocalDateTime ldt) {
		// declare and initialize local time
		LocalTime lTime;
		// get ZonesDateTime from the given LocalDateTime
		ZonedDateTime ldtZoned = ldt.atZone(ZoneId.systemDefault());
		// get UTC ZonedDateTime
		ZonedDateTime utcZoned = ldtZoned.withZoneSameInstant(ZoneId.of("UTC"));
		lTime =  utcZoned.toLocalTime();
		// pass UTC date to the main method.
	    return lTime;
	}
}

Output: