How to get Time in Milliseconds for the Given date and time in Java?

The java.text.SimpleDateFormat class is used to format and parse a string to date and date to string.

• One of the constructors of this class accepts a String value representing the desired date format and creates SimpleDateFormat object. 
• To parse/convert a string as a Date object Instantiate this class by passing desired format string.
• Parse the date string using the parse() method.
• You can get the epoch time using the getTime() method.

Example

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Sample {
   public static void main(String args[]) throws ParseException {  
      //Instantiating the SimpleDateFormat class
      SimpleDateFormat dateformatter = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");      
      //Parsing the given String to Date object
      String str = "25-08-2009 11:20:45";
      Date date = dateformatter.parse(str);  
      long msec = date.getTime();
      System.out.println("Epoch of the given date: "+msec);
   }
}

Output

Epoch of the given date: 1251179445000

You can set date and time values to a calendar object using the set() method. The getTimeInMillis() of this class returns the epoch time of the date value.

Example

import java.util.Calendar;
public class Sample {
   public static void main(String args[]) {  
      Calendar cal = Calendar.getInstance();
      cal.set(2014, 9, 11, 10, 25, 30);
      long msec = cal.getTimeInMillis();
      System.out.print(msec);      
   }
}

Output

1413003330758

You can set date and time values to a ZonedDateTime object using the of() method. The toEpochMilli() of the Instant class returns the epoch time of the date value.

Example

import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;
public class Sample {
   public static void main(String args[]){  
      //Creating the ZonedDateTime object
      ZoneId id = ZoneId.of("Asia/Kolkata");
      ZonedDateTime obj = ZonedDateTime.of(2014, 9, 11, 10, 25, 30, 22, id);
      Instant instant = obj.toInstant();      
      long msec = instant.toEpochMilli();
      System.out.println("Milli Seconds: "+msec);
   }
}

Output

Milli Seconds: 1410411330000