Problems creating a particular matrix (multiple dates of reference)

I managed it somehow: I created a master calendar, linked it by subscription and unsubscription. then used these formulas:

NumberOfSubscriptions = COUNTROWS(RELATEDTABLE('user_info'))

NumberOfUnsubscriptions = CALCULATE(COUNTROWS(RELATEDTABLE('user_info')); USERELATIONSHIP('Master Calendar'[MasterDate]; 'user'[UnsubscribeDate]))

so now I have the number of subscriptions and unsubscriptions for each date.

But I'd like to avoid to use the master calendar for other purposed.

Can someone suggest me another way to do it?