1. Log into the Gmail Account you want to copy calendar items from and Click the Google Apps icon.
2. Open the Google Calendar Web App.
3. Click on the ... next to one of your calendars.
4. Click on 'Settings and sharing'
5. Click on 'Import & export'
6. Click on 'Export'
To Import the Calendar Data into Another Gmail Account’s Calendar
1. Log into your other Gmail account and repeat steps 1-5.
2. Click on Select file from your computer and select the calendar file you just exported from the previous Gmail calendar.
3. Select the folder you want to add the calendar events to.
4. Select Import.