DateUtil From Puffin Core, and stackoverflow Or you could just use DateUtils from apache library, it is much better

DateUtil.java

// Date Time Utils

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.time.*;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;

/**
 * All date time are default to utc
 * Created by Fuxing
 * Date: 21/1/2015
 * Time: 12:51 AM
 * Project: PuffinCore
 */
public final class DateUtil {
    private DateUtil() {/* NOT Suppose to init */}

    public static final String STRING_DATE_FORMAT = "dd-MM-yyyy hh:mm:ss";
    public static final DateFormat DateFormat = new SimpleDateFormat(STRING_DATE_FORMAT);

    /**
     * @return Current millis
     */
    public static long millisNow() {
        return System.currentTimeMillis();
    }

    /**
     * @return Current date
     */
    public static Date now() {
        return new Date(millisNow());
    }

    public static Instant instanceNow() {
        return zonedNow().toInstant();
    }

    public static ZonedDateTime zonedNow() {
        return ZonedDateTime.now(ZoneId.of("UTC"));
    }

    public static LocalDateTime localNow() {
        return zonedNow().toLocalDateTime();
    }

    public static LocalTime timeNow() {
        return zonedNow().toLocalTime();
    }

    public static ZonedDateTime toZonedDateTime(Date date) {
        return ZonedDateTime.ofInstant(date.toInstant(), ZoneId.of("UTC"));
    }

    public static Date addYears(Date date, int years){
        return add(date, Calendar.YEAR, years);
    }

    public static Date addMonths(Date date, int months){
        return add(date, Calendar.MONTH, months);
    }

    public static Date addDays(Date date, int days) {
        return add(date, Calendar.DATE, days);
    }

    public static Date addMinutes(Date date, int minutes) {
        return add(date, Calendar.MINUTE, minutes);
    }

    public static Date addSeconds(Date date, int seconds){
        return add(date, Calendar.SECOND, seconds);
    }

    public static Date addMillis(Date date, int millis){
        return add(date, Calendar.MILLISECOND, millis);
    }

    /**
     * @param date date to edit
     * @param type type of edit
     * @param unit units to edit
     * @return edited date
     */
    public static Date add(Date date, final int type, int unit) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.add(type, unit);
        return cal.getTime();
    }

    /**
     * @param date date to convert to string
     * @return string data with standard format
     */
    public static String toString(Date date) {
        return DateFormat.format(date);
    }

    /**
     * @param date date to convert to string
     * @return Singapore string data with standard format
     */
    public static String toSgString(Date date) {
        return toZonedDateTime(date).format(DateTimeFormatter.ofPattern(STRING_DATE_FORMAT, Locale.ENGLISH).withZone(ZoneId.of("GMT+8")));
    }
}