cat tz
LC_ALL=C TZ=UTC0

date -f tz
date: invalid date ”LC_ALL=C TZ=UTC0”

cat date
#!/bin/bash

LC_ALL=C TZ=UTC0 date

./date
Tue Sep 27 06:56:29 UTC 2016

date
tis 27 sep 2016 08:56:52 CEST