I don't know about "easy", but you can always check the log. Here's a snippet from mine.
3 6/17/2018 5:54:05 PM Carport MOTION
3 6/17/2018 5:55:56 PM FrontNorth MOTION
3 6/17/2018 5:56:08 PM Carport MOTION
Another maybe not easy way is in UI3. Click on the camera to display it and select the date you want. Then highlight all clips, right click and it will show you how many have been selected. Then just cancel out.