Convert LocalDateTime to java.util.Calendar Object in Java

Below are steps to convert the Java LocalDateTime object into java.util.Calendar object,

Step 1: We will create an object of Java 8 Date-Time API LocalDateTime class.

LocalDateTime localDateTime = LocalDateTime.now();

Step 2: Next, we will create an object of ZoneId that will be required to convert LocalDate time to ZonedDateTime.

ZoneId zoneId = ZoneId.systemDefault();

Step 3: We now convert LocalDateTime to ZonedDateTime object

ZonedDateTime zonedDateTime = localDateTime.atZone(zoneId);

Step 4:We create an instance of Calendar class.

Calendar calendar = Calendar.getInstance();

Step 5: Finally we get the epoch time in milliseconds from zonedDateTime and set it to calendar object.

calendar.setTimeInMillis(zonedDateTime.toInstant().toEpochMilli());

Complete Code:

import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.Calendar;

public class LocalDateTimeToCalendarExample {

    public static void main(String[] args) {

        LocalDateTime now = LocalDateTime.now();
        ZoneId zoneId = ZoneId.systemDefault();
        ZonedDateTime zonedDateTime = now.atZone(zoneId);
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(zonedDateTime.toInstant().toEpochMilli());

    }
}

References:

• java.time.LocalDateTime: https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/time/LocalDateTime.html
• java.time.ZoneId: https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/time/ZoneId.html
• java.time.ZonedDateTime: https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/time/ZonedDateTime.html
• java.util.Calendar: https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Calendar.html