If you are not getting the latest events pushed to your Google Calendars, you may have to re-add the calendar to your page. The Master Calendar will be used as an example. To do this, follow these steps:
1. Go To Calendar Settings: Open http://calendar.google.com. On the left side of the page, click the down arrow to the right of "Other Calendars". Click "Settings".
2. Remove the Calendar: Click the "Unsubscribe" link next to the calendar you want to remove. In the confirmation box, click "Unsubscribe".
From the Navigation links on the left, find the calendar you want to add and click on the link. Click on the Google Calendar Icon in the lower right corner of the calendar you chose. It will automatically open your Google Calendar page and ask if you would like to add the calendar. Select "Yes"
4. Change the Name (optional): The calendar may not be added with the name you want to see (If you did this with the master calendar, then it will appear with the name "Events"). You can change the display name of the calendar to something else. On the left side of the page, click the down arrow to the right of calendar you just added and select "Calendar settings".
Under calendar name, change it to your preferred name then click save.
Your calendar should now show all the updated events. Repeat this process for each calendar that is not updating correctly.