Calculate time intelligence measures based on user selection from two different types of dates

Hi PandaPacifica , The field parameter feauture of PBI can solve your problem. Please follow the below link; 

https://www.phdata.io/blog/what-are-field-parameters-in-power-bi/

There is a tricky condition here. If you model your date table by "Customer Order Date", you have to use "Userrelationship" function to provide "System Booked Date" calculation. I think so , you used your master date table in all your pages to filter time. If you use "passive relationship" and "userrelationship" , system will be worked. Please follow the below link; 

https://dax.guide/userelationship/

If you cannot reach your goal by the above mentioned solution, please give me detail your bottleneck step by step, I try to help solving the problem. 

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.