Google Notification

eginning August 1st 2011, we’ll support the current and prior major release of Chrome, Firefox, Internet Explorer and Safari on a rolling basis. Each time a new version is released, we’ll begin supporting the update and stop supporting the third-oldest version three months after the release.

As of August 1st 2011, we will discontinue support for the following browsers and their predecessors: Firefox 3.5, Internet Explorer 7, and Safari 3. Chrome updates you to the latest version automatically, so you don’t need to worry about which version you have. In older browsers you may have trouble using certain features in Google Calendar or they may stop working entirely.
We encourage you to get the latest version of your favorite browser.

• Google Chrome (for Windows, Mac, and Linux) Download
• Microsoft Internet Explorer (IE) for Windows Download
• Mozilla Firefox (for Windows, Mac and Linux) Download
• Safari for Mac OS X Download

Note: JavaScript and cookies must be enabled on all browsers.

Source : Google