Java 8 – Convert Instant to LocalDateTime

Java 8 examples to show you how to convert from Instant to LocalDateTime

1. Instant -> LocalDateTime

The java.time.LocalDateTime has no concept of time zone, just provide a zero offset UTC+0.

InstantExample1.java

package com.favtuts.time;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneOffset;

public class InstantToLocalDateTime {

    public static void main(String[] args) {
        convertInstantToLocalDateTime();
    }

    static void convertInstantToLocalDateTime() {
        // Parse a ISO 8601 Date directly
	//Instant instant = Instant.parse("2016-08-18T06:17:10.225Z");

        Instant instant = Instant.now();

        System.out.println("Instant : " + instant);

        //Convert instant to LocalDateTime, no timezone, add a zero offset / UTC+0
        LocalDateTime ldt = LocalDateTime.ofInstant(instant, ZoneOffset.UTC);

        System.out.println("LocalDateTime : " + ldt);
    }
}

Output

Instant : 2016-08-18T06:17:10.225Z
LocalDateTime : 2016-08-18T06:17:10.225

2. LocalDateTime -> Instant

InstantExample2.java

package com.favtuts.time;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.Month;
import java.time.ZoneOffset;

public class InstantToLocalDateTime {

    public static void main(String[] args) {
        convertLocalDateTimeToInstant();
    }

    static void convertLocalDateTimeToInstant() {
        // Hard code a date time
        LocalDateTime dateTime = LocalDateTime.of(2016, Month.AUGUST, 18, 6, 17, 10);

        System.out.println("LocalDateTime : " + dateTime);

        // Convert LocalDateTime to Instant, UTC+0
        Instant instant = dateTime.toInstant(ZoneOffset.UTC);

        System.out.println("Instant : " + instant);
    }
}

Output

LocalDateTime : 2016-08-18T06:17:10
Instant : 2016-08-18T06:17:10Z

Download Source Code

$ git clone https://github.com/favtuts/java-core-tutorials-examples

$ cd java-basic/time

References

1. Wikipedia – ISO 8601 date format
2. Instant JavaDoc
3. LocaldateTime JavaDoc