Check handling of time of 24:00 

```
This SO question:

http://stackoverflow.com/questions/13527292

led me to consider whether we can parse date/times such as

2012-11-23T24:00:00

which is permitted by ISO-8601 and should be equivalent to

2012-11-24T00:00:00
```

Original issue reported on code.google.com by `jonathan.skeet` on 23 Nov 2012 at 10:43
