Block Sites not compatible with Firewall Rules

[Apollo18]

I find that I can either use the Block Sites feature to prevent access to certain websites;
OR,
I can block all access during a schedule window;
BUT NOT BOTH.

Block Sites works as expected as long as I have no Firewall Rules defined.
However, when I add the rule:

Any(ALL) BLOCK by schedule, otherwise Allow Any Any Never

This seems to overrule the Block-Sites setting and the sites I have blocked become freely accessible again.

Is there any way to have selected sites blocked permanently, AND, have ALL sites blocked during a specified time window?

[jmizoguchi]

Use opendns and filter the site