Question

I have a database for members that calculates their attendance via roll up from another events database. How can I filter the rollup to count the number of events a member goes to after a certain date? I've tried using tags and using a formula to restrict the attended members at each event and I'm stuck.

Answer 1

You can try this formula instead of using rollup.

prop("Events")
    .filter(current.prop("Date").formatDate("YYYY") == formatDate(now(), "YYYY"))
    .length()

It's currently filtering and counting how many events the member has participated for this year. You can simply change the now() to the year you desire.

Here's the template and the formula inside:
https://thomasyang.notion.site/Notion-Calendar-Filter-11cf60eceaf680c0b765f88badb5ac06?pvs=4