Combine specific folder restriction with request time

I need to create a rule which prevents sync for a specific folder from 8.00am to 21.00pm. The problem is that I have 1 laptop and 2 pc’s and during the daytime we work with the same folder shared in NC15. And it’s a FoxPro based app with dbf files and other stuff witch we access in the same time so, normally, a lot of conflict files appear.
So, we taught is simpler if we create a rule which prevents synchronizing that shared folder from 8am till 9pm. But the rest of the sync folders must remain sync during this time.
Help is really appreciated.