--- a/src/libstdc++-v3/scripts/run_doxygen
+++ b/src/libstdc++-v3/scripts/run_doxygen
@@ -130,7 +130,9 @@ do_latex=false
 latex_cmd=
 enabled_sections=
 generate_tagfile=
-DATEtext=`date '+%Y-%m-%d'`
+DATE_FMT="+%Y-%m-%d"
+SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH:-$(date +%s)}"
+DATEtext=`date -u -d "@$SOURCE_DATE_EPOCH" "$DATE_FMT" 2>/dev/null || date -u -r "$SOURCE_DATE_EPOCH" "$DATE_FMT" 2>/dev/null || date -u "$DATE_FMT"`
 
 # Show how this script is called.
 echo run_doxygen $*