-echo "###################################" > "$CRONTAB"
-echo "$HEADER_WARNING" >> "$CRONTAB"
-echo "###################################" >> "$CRONTAB"
-echo >> "$CRONTAB"
-echo "# It was generated from '$DIRECTORY/*' on `date -R`." >> "$CRONTAB"
+echo '###################################' >"$CRONTAB"
+echo "$HEADER_WARNING" >>"$CRONTAB"
+echo '###################################' >>"$CRONTAB"
+echo >>"$CRONTAB"
+printf "# It was generated from '%s/*' on %s." \
+ "$DIRECTORY" "`LANG=C date '+%a, %d %b %Y %H:%M:%S %z'`" >>"$CRONTAB"