/// <summary>
        /// Returns an <see cref="Interval"/> representing the local date in the given time zone.
        /// </summary>
        /// <param name="date">A local date.</param>
        /// <param name="timeZone">A time zone.</param>
        /// <returns></returns>
        public static Interval ToIntervalInZone(this LocalDate date, DateTimeZone timeZone)
        {
            var start = timeZone.AtStartOfDay(date);
            var end   = timeZone.AtEndOfDay(date);

            return(new Interval(start.ToInstant(), end.ToInstant()));
        }