@@ -248,7 +248,7 @@ Grafana has global built-in variables that can be used in expressions in the que
### Time range variables
Grafana has two built in time range variables in `$__from` and `$__to`. They are currently always interpolated
-as epoch milliseconds.
+as epoch milliseconds. These variables are only available in Grafana v6.0 and above.
### The $__interval Variable