The date range formatting in Tiger is almost uncontrollable. With a typical U.S. date format of MMM d, yyyy, I get what you see in OKDates.png when the images in the album span more than one month. But when they're in the same month, I get what you see in awfulDates.png.
Please just give us the starting and ending dates (and times, if specified in the format string), using the specified date format. If the starting and ending dates are identical, show only one. But if they differ in any way, show us the full beginning date and full ending date.
Attempts to get fancy with this are clearly not working.
BTW, an option to eliminate the time when putting together the range on the hero image might be nice. A user may want to show time when displaying photo data, but when showing a date range, the time is usually superfluous.
Sorry, date range can only handle dates. It was a hard to figure out the dates alone, I didn't even try to add time. Perhaps I will add some warning or remove times automatically. The formatter watches spaces slash and dash, I wasn't aware of commas so far.
I don't think it's possible to come up with one solution that works for all regional variations in date formatting. What works for a U.S. style date won't work for a European style date. And there isn't a single style used in either place - there are multiple variations.