I see. Let me try a few tests. Although the Calendar is not tuned as much as the Scheduler, 100 events should be no problem at all. 6 minutes equals to 3.6 seconds per event. This is what I would expect to be the total time of the client-side rendering.
I would suggest the following:
1. Please try to capture the network traffic during the update using IE 9 or higher and send the NetworkData.xml to support@daypilot.org. See also here:
http://kb.daypilot.org/81542/how-to-record-network-activity-using-ie-developer-tools/
2. Try to profile the JavaScript activity using of the browser developer tools (IE, Chrome, Firefox + Firebug). You should see how the browser spends the time. If there is anything interesting, please send it to support@daypilot.org as well.