Google Calendar for Android is now an app of its own for non-Nexus devices.

My first Android device was the Nexus One and ever since I had it, I never thought of getting any other Android phone that wasn't a Nexus. I skipped the Nexus S and got the Galaxy Nexus. Today I realized how things are different in the Nexus world compared to the other Android phones out there. Of course, the Nexus devices are stock Android and get updates faster than the others. The others very often do not get more than one update or none at all. But the differences is not limited to updates. 
Today I found out that the Calendar app on my Gnux, which is a stand-alone app does not have the same status on other devices. The other phones's Calendar were still built into the OS. That has changed now that Google has posted a new Calendar app to the Play Store for the other devices running Android 4.0 or later. For once, these other devices will have extra features not yet available on the Nexus:

• Snooze events directly from a notification if you’re not quite ready and want to be reminded later.
• Use predefined messages to send quick "I'll be late" updates to your event participants directly from the notifications or the event itself (of course, you can always write your own).
• Pinch to zoom in and out of a day.
• Set a home time zone to help you manage your time better when traveling.

Download Google Calendar on Play Store.

Source: Official Android Blog