The source project of this merge request has been removed.
Allow to override man-page date with SOURCE_DATE_EPOCH
in order to make builds reproducible.
See https://reproducible-builds.org/ for why this is good
and https://reproducible-builds.org/specs/source-date-epoch/
for the definition of this variable.
Also use UTC via gmtime to be independent of timezone.
This patch was done while working on reproducible builds for openSUSE.