Thank you Nicolai.
I was able to locate the calendardb file in /home/user/.calendar/ and it seems to still exist, but the calender program isn't loading it. Looks like the file size is 1.2M. It seems like the n900 has made a backup file of it (on it's own). My husband (very familiar with xterm) helped me copy the backup over the calendardb file. They loaded, but a lot of entries and calendars were still missing. On reboot, they again wouldn't load.
Any thoughts?

I did get a response from Nokia tech support, but it was useless. He told me how sorry he was that I was having calendar problems on my n90 and the only way to get it back was to do a restore from my 10 day old backup. He also suggested I sync my n90 with Ovi.
I responded that I had a N Nine Hundred and that it wasn't compatible with Ovi and to please forward my email to some more advanced tech support.

Thanks again,
Robin