Jekyll does not support this value for Page or Post classes. The
capture returned an empty Sting, which was always evaluated to true
in '{% if updated %}'.
A new config variable 'date_format' is introduced in _config.yml.
It can either be set to "ordinal" to use the current format or it
can be given a string complying to strftime() format identifiers.
Frederic Hemberger
Brandon Mathis