If Doxyfile contains HTML_TIMESTAMP = YES, Doxygen will add a timestamp to its generated (HTML) documentation.

It seems Doxygen has no way to turn it off for man-pages, see ReproducibleBuilds/TimestampsInManpagesGeneratedByDoxygen.

A good amount of potentially affected packages can be found using codesearch.

Known affected packages

Detection

Example debbindiff output

Solution

A patch has been sent to Doxygen upstream which honours the implementation of the new environment variable SOURCE_DATE_EPOCH. This was proposed as a way to produce deterministic timestamps [1].

Upstream bug:https://bugzilla.gnome.org/show_bug.cgi?id=751984

This solution avoids having to carry a patch against upstream (only if doxygen is called in debian/rules):

override_dh_auto_build-indep:
    { cat Doxyfile && echo "HTML_TIMESTAMP=NO"; } | doxygen -

Otherwise, patch upstream

Example patch 1, Example patch 2

[1] https://wiki.debian.org/ReproducibleBuilds/TimestampsProposal