If it’s just your wife’s phone (this solution doesn’t scale) and only on Fridays, you could do something like this:
Instead of direct modifications to your blacklist (like the example), you could change CFW or FMFM the same way, then kick the job off from ‘crontab -e asterisk -u’. You can use the fwconsole command to check out the various database objects you can manhandle this way and make your changes at will.
The advantage - to turn it off early, you can just use the standard Asterisk Feature Codes to turn them on and off from her phone if desired.