@Gary_Milne, we have released the Variables for Dashboard and Rule Engine features to SharpTools.io today, and I think you might be interested to give it a shot. 
You can create a True/False variable and use this variable in the rules to decide the rules should continue execution or not. This variable can also be added to the dashboard, so you can enable/disable multiple rules in the same time by tapping this variable tile in the dashboard without the need of using Virtual Switch.
See the release post for more details and let me know if you have any questions. (Date/time variable types are still in my list and are not available in this release.)