java-tutorials/java-dates/src/test/java/com/baeldung/dateapi/ConversionExample.java

package com.baeldung.dateapi;

import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.TimeZone;

public class ConversionExample {
    public static void main(String[] args) {
        Instant instantFromCalendar = GregorianCalendar.getInstance().toInstant();
        ZonedDateTime zonedDateTimeFromCalendar = new GregorianCalendar().toZonedDateTime();
        Date dateFromInstant = Date.from(Instant.now());
        GregorianCalendar calendarFromZonedDateTime = GregorianCalendar.from(ZonedDateTime.now());
        Instant instantFromDate = new Date().toInstant();
        ZoneId zoneIdFromTimeZone = TimeZone.getTimeZone("PST").toZoneId();
    }
}