I modified my subscription, but Google Calendar is not updated. Why?

Google Calendar updates calendar subscriptions every 12 or 24 hours. There is no way for the user to force Google Calendar to update more often. You can either just wait up to 24 hours for Google Calendar to update, or you can change the subscription identifier. When the identifier is changed, Google doesn't find the calendar in its cache and is forced to download it.

Step 1
First, delete the current calendar subscription from Google. Log in to Google Calendar, take a look in the panel in the left side. If needed, open Other calendars by clicking to show the calendars. Then click to unsubscribe from that calendar.
First, delete the current calendar subscription from Google. Log in to Google Calendar, take a look in the panel in the left side. If needed, open Other calendars by clicking  to show the calendars. Then click  to unsubscribe from that calendar.
Step 2
Open the menu by clicking and select Change subscription identifier.
Open the menu by clicking  and select Change subscription identifier.
Step 3
Add the calendar with the new subscription identifier back to Google. Click and select Add to Google Calendar.
Add the calendar with the new subscription identifier back to Google. Click  and select Add to Google Calendar.
Step 4
You will be taken to Google Calendar. Log in if necessary. Then click Add.
You will be taken to Google Calendar. Log in if necessary. Then click Add.
Step 5
The name of the calendar in the left panel may look odd.
The name of the calendar in the left panel may look odd.
Step 6
A simple page refresh will reveal the correct name.
A simple page refresh will reveal the correct name.