To Export a calendar from your old Google account.
1. In the calendar list on the left side of the page, click the down-arrow next to the appropriate calendar and select Calendar settings. (Alternatively, click the Settings link at the bottom of the calendar list, then click the appropriate calendar.)
2. Click the ICAL button in the 'Private Address' section at the bottom of the page, and control-click the displayed URL.
3. Save the exported file to the desired folder on your computer.
To Import a downloaded calendar to your new Google account.
1. Click the Add down-arrow button at the bottom of the calendar list on the left side of the page, and select Import Calendar.
2. Click Browse and choose the file that contains your events, then click Open.
3. Select the Google Calendar where you'd like to import events, then click Import.