Disallow multiline and comments inside timestamps

[WebFreak001]

timestamps like this needlessly complicate the parsing and things like formatters, this kind of thing should be forbidden:

// these are valid timestamps:
2013/2/22/*foo*/07:53

2013/2/22 /*foo*/ \
  /*bar*/ 07:53

2013/2/22 /*foo*/ \
\
  \
  /*bar*/ 07:53

this is a wishlist item for spec v2