Counting current quarters activities

Hi All,

  I am working on a field to count the current quarters activities, which are made up of calls and meetings. I have built an integer field on each module to count the necessary calls or meetings. I am trying to bring in the sum of the two modules onto the account module but i only want to bring in current quarter activities. I am able to successfully bring in a total count but how can i limit this down to only current quarter? My goal is to build this field and not have to refresh it every quarter to make it work. here is my current formula

add(
rollupSum($calls,"activity_count_c"),
rollupSum($meetings,"activity_count_c")
)