The implementation of span_range (and also interval()) is surprising to me, and is not what I would expect from a range function.

            >>> start = datetime(2013, 5, 5, 12, 30)
            >>> end = datetime(2013, 5, 5, 17, 15)
            >>> for r in arrow.Arrow.span_range('hour', start, end):
            ...     print(r)
            ...
            (<Arrow [2013-05-05T12:00:0

I'd like an /Examples folder with some simple iOS apps showing how to use Time.

The first one that comes to mind is a basic iOS app using a UICollectionView to build a month calendar view.

This is related to #410 and #859, we currently only support a limited subset of possible values for RDATE, but we should support all the parameters in RDATE, the grammar for which is set out in RFC 5545:

       rdate      = "RDATE" rdtparam ":" rdtval *("," rdtval) CRLF

       rdtparam   = *(
                  ;
                  ; T