diff --git a/util/genbuild_h/genbuild_h.sh b/util/genbuild_h/genbuild_h.sh
index d500d252bd..d814ce58e7 100755
--- a/util/genbuild_h/genbuild_h.sh
+++ b/util/genbuild_h/genbuild_h.sh
@@ -18,6 +18,8 @@
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 #
 
+DATE=$(date +%s)
+
 #Print out the information that goes into build.h
 printf "/* build system definitions (autogenerated) */\n"
 printf "#ifndef __BUILD_H\n"
@@ -31,17 +33,17 @@ if [ -d "${top}/.git" ] && [ -f "$(command -v git)" ]; then
 	printf "#define COREBOOT_ORIGIN_GIT_REVISION \"%s\"\n" "$(LANG= git log remotes/origin/master -1 --format=format:%h)"
 else
 	printf "/* `LANG= TZ=UTC date` */\n"
-	printf "#define COREBOOT_VERSION_TIMESTAMP %s\n" "$(LANG= date +%s)"
+	printf "#define COREBOOT_VERSION_TIMESTAMP %s\n" "$(LANG= date -d @$DATE +%s)"
 	printf "#define COREBOOT_ORIGIN_GIT_REVISION \"Unknown\"\n"
 fi
 
 printf "#define COREBOOT_EXTRA_VERSION \"%s\"\n" "$COREBOOT_EXTRA_VERSION"
-printf "#define COREBOOT_BUILD \"%s\"\n" "$(date)"
-printf "#define COREBOOT_BUILD_YEAR_BCD 0x%s\n" "$(date +%y)"
-printf "#define COREBOOT_BUILD_MONTH_BCD 0x%s\n" "$(date +%m)"
-printf "#define COREBOOT_BUILD_DAY_BCD 0x%s\n" "$(date +%d)"
-printf "#define COREBOOT_BUILD_WEEKDAY_BCD 0x%s\n" "$(date +%w)"
-printf "#define COREBOOT_DMI_DATE \"%s\"\n" "$(date +%m/%d/%Y)"
+printf "#define COREBOOT_BUILD \"%s\"\n" "$(date-d @$DATE)"
+printf "#define COREBOOT_BUILD_YEAR_BCD 0x%s\n" "$(date -d @$DATE +%y)"
+printf "#define COREBOOT_BUILD_MONTH_BCD 0x%s\n" "$(date -d @$DATE +%m)"
+printf "#define COREBOOT_BUILD_DAY_BCD 0x%s\n" "$(date -d @$DATE +%d)"
+printf "#define COREBOOT_BUILD_WEEKDAY_BCD 0x%s\n" "$(date -d @$DATE +%w)"
+printf "#define COREBOOT_DMI_DATE \"%s\"\n" "$(date -d @$DATE +%m/%d/%Y)"
 printf "\n"
-printf "#define COREBOOT_COMPILE_TIME \"%s\"\n" "$(date +%T)"
+printf "#define COREBOOT_COMPILE_TIME \"%s\"\n" "$(date -d @$DATE +%T)"
 printf "#endif\n"