Hi @Neville,
Yes ou can just maintain one date table and have
- Active relationship between the date table and Closed Date.
- Inactive relationship between the date table and Revenue Date.
The active relationship will work as normal but for inactive relationship you need to use USERELATIONSHIP function. Please refer below discussion which has good links describing how to achieve it.
https://info.enterprisedna.co/dax-function-guide/userelationship/