If you use Google Calendar, then before Thursday, you will want to go to mozilla.org and download their free calendar application in either SeaMonkey or SunBird. If you use Mac, then just use the iCal.
When you have that application installed and running, go to your calendar.google.com and click on settings, then calendars, then your main calendar. Then at the bottom of the Calendar Details page there is a private address.
Right mouse copy link location the "iCal" icon in the private address area and then go to your running calendar applicaiton (sunbird, seamonkey, or mac's ical). and in the left panel right click and chose subscribe and paste the ical link you just copied into the Calendar Url field and save. This should subscribe you to your google calendar so that you can use it while calendar.google.com is down.
Then when calendar.google.com comes back up better than ever, you can resync from your calendar application back to your calendar.google.com calendar.
If you want to share your private link with me because you normally share your calendar, that would be fine... Just an idea.
This is the best way to backup your calendar from calendar.google.com for future reference.
---------- Forwarded message ----------
We wanted to inform you that we are planning to conduct routine maintenance to Google Calendar between 8AM and 9PM on Thursday, April 26th, 2007 . During this time, this service may be unavailable to some of your users. Please inform your users about this planned maintenance appropriately. We apologize for the inconvenience and appreciate your patience as we work to improve Google Calendar.
If you have any questions, you can contact the Google Apps Support team through the Google Apps Help center ( http://www.google.com/support/a/).
The Google Apps Team
Please do not reply directly to this message. Please contact us through the Google Apps Help Center ( http://www.google.com/support/a/) if you have any questions.