Using dynamic current date in change stream pipeline

I have a situation where we want to filter a change stream and receive changes only when a Date field in our document is in the past. When the service is started we pass an $lt filter for the current UTC date using c#. However, the service runs for a very long time and so the fixed date reference prevents us from getting documents where the Date field in question has passed.

Ultimately, I am trying to figure out if there is a way for the match in the pipeline provided to the watch to use the current utc date at the time of change.

I am relatively new to using MongoDB so please feel free ask for more info or provided hints at better wording for my question.