class DateUtils {

    public static Date getNextDate( int hourOfDay, Date now )
    {
        now = now != null ? now : new Date();

        DateTime date = new DateTime( now ).plusHours( 1 );

        while ( date.getHourOfDay() != hourOfDay )
        {
            date = date.plusHours( 1 );
        }

        return date
            .withMinuteOfHour( 0 )
            .withSecondOfMinute( 0 )
            .withMillisOfSecond( 0 )
            .toDate();
    }

}