merged upstream <https://savannah.gnu.org/bugs/?54367>

Index: gettext-0.19.8.1/gettext-runtime/man/help2man
===================================================================
--- gettext-0.19.8.1.orig/gettext-runtime/man/help2man
+++ gettext-0.19.8.1/gettext-runtime/man/help2man
@@ -179,7 +179,7 @@ my ($help_text, $version_text) = map {
 	or die "$this_program: can't get `--$_' info from $ARGV[0]\n"
 } qw(help version);
 
-my $date = strftime "%B %Y", localtime;
+my $date = strftime "%B %Y", gmtime($ENV{SOURCE_DATE_EPOCH} || time);
 (my $program = $ARGV[0]) =~ s!.*/!!;
 my $package = $program;
 my $version;
Index: gettext-0.19.8.1/gettext-tools/man/help2man
===================================================================
--- gettext-0.19.8.1.orig/gettext-tools/man/help2man
+++ gettext-0.19.8.1/gettext-tools/man/help2man
@@ -179,7 +179,7 @@ my ($help_text, $version_text) = map {
 	or die "$this_program: can't get `--$_' info from $ARGV[0]\n"
 } qw(help version);
 
-my $date = strftime "%B %Y", localtime;
+my $date = strftime "%B %Y", gmtime($ENV{SOURCE_DATE_EPOCH} || time);
 (my $program = $ARGV[0]) =~ s!.*/!!;
 my $package = $program;
 my $version;