Creates an interval between two dates with normalized date list representation.
与 .wl 参考的差异： `DateInterval` canonical form
DateInterval[{start, end}]
DateInterval[{start, end}, gran]
DateInterval[{{start1, end1}, {start2, end2}, …}]
DateInterval[gdate]
- CalendarType — default Automatic
- DateFormat — default Automatic
- DateGranularity — default Automatic
- TimeSystem — default Automatic
- TimeZone — default Automatic