Google Labs provides a gadget that can be turned on to display your calendar in the lower left side of the screen while you are in looking at your mail.

To see your upcoming calendar within your email:

1. Go to the settings on top right of the email, it looks like a gear

2. Open the drop down menu, click on settings

3. Across the top in blue, look for word "labs" click on it

4. Scroll down until you find the "Google Calendar gadget", and click enable

5. go to the bottom of the page, click save changes

6. go back to your inbox, then on the bottom left of the page below your compose button at the very bottom, you will see a grey box with 3 black dots in it, click the box and the calendar will pop up below your folders on the left