diff --git a/scripts/portable_date.sh b/scripts/portable_date.sh
new file mode 100755
index 0000000000..84a18eb621
--- /dev/null
+++ b/scripts/portable_date.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+case $(uname) in
+	NetBSD|OpenBSD|DragonFly|FreeBSD|Darwin)
+		date -r $1 $2
+		;;
+	*)
+		date -d @$1 $2
+esac
+
+exit $?