A source URL without the {DATE} placeholder is date-invariant, so its
HEAD probe always answers 200. Including such sources in the freshness
check made the checker report "server has a newer version" regardless
of the dated sources' state.
A source URL without the {DATE} placeholder is date-invariant, so its
HEAD probe always answers 200. Including such sources in the freshness
check made the checker report "server has a newer version" regardless
of the dated sources' state.