The toEpochSecond() method of a ChronoZonedDateTime interface is used to convert this ChronoZonedDateTime to the number of seconds since the epoch of 1970-01-01T00:00:00Z. The method combines this ChronoZonedDateTime with the offset passed as parameters to calculate the epoch-second value, which is the number of elapsed seconds from 1970-01-01T00:00:00Z. Instants on the timeline after the epoch are positive, earlier are negative.
Syntax:
default long toEpochSecond()
Parameters: This method do not accepts any parameter.
Return value: This method returns long which is the number of seconds since the epoch of 1970-01-01T00:00:00Z, may be negative.
Below programs illustrate the toEpochSecond() method:
Program 1:
// Java program to demonstrate// ChronoZonedDateTime.toEpochSecond() method  import java.time.*;import java.time.chrono.*;import java.time.chrono.*;  public class GFG {    public static void main(String[] args)    {          // create ChronoZonedDateTime object        ChronoZonedDateTime time            = ZonedDateTime                  .parse(                      "2018-12-06T19:21:12.123+05:30[Asia/Calcutta]");          // print ChronoZonedDateTime        System.out.println("ChronoZonedDateTime: "                           + time);          // print result        System.out.println("Epoch Second: "                           + time.toEpochSecond());    }} |
ChronoZonedDateTime: 2018-12-06T19:21:12.123+05:30[Asia/Calcutta] Epoch Second: 1544104272
Program 2:
// Java program to demonstrate// ChronoZonedDateTime.toEpochSecond() method  import java.time.*;import java.time.chrono.*;import java.time.chrono.*;  public class GFG {    public static void main(String[] args)    {          // create ChronoZonedDateTime object        ChronoZonedDateTime time            = ZonedDateTime.parse(                "1918-10-25T23:12:38.543+02:00[Europe/Paris]");          // print ChronoZonedDateTime        System.out.println("ChronoZonedDateTime: "                           + time);          // print result        System.out.println("Epoch Second: "                           + time.toEpochSecond());    }} |
ChronoZonedDateTime: 1918-10-25T23:12:38.543Z[Europe/Paris] Epoch Second: -1615250842
Reference: https://docs.oracle.com/javase/9/docs/api/java/time/chrono/ChronoZonedDateTime.html#toEpochSecond–
