Google Calendar will easily allow you to include multiple calendar topics in a single calendar, but Google Sites only imports one at a time into its calendar feature. It is possible to merge multiple calendars together into a single Google Sites calendar and have it feed automatically. The first steps in the process are to create the Google calendar with all needed topics as well as the basic Google Sites Page with an embedded calendar feature. Once completed do the following:
1. Click setting on the left under your list of calendar topics.
2. Click on the name of 1 of the calendar topics.
3. Under embed this calendar, click customize the color, size, and other…
4. Select the calendar topics on the left you would like to feed into the Google Sites calendar.
5. Click the Update HTML button on the top right.
6. Highlight and copy the HTML code displayed.
1. Click edit page.
2. Click in the box where the calendar feature is embedded.
3. Select the small html icon on the bar at the top.
4. Copy and replace the existing HTML with the new code you just copied from the Google Calendar site.
5. Click update.
Your Google Sites calendar will now feed and update automatically from you Google Calendar for all the topics you selected.