DAVical and Open Source Calendar Migration to Exchange / Office 365

We got an inquiry a while back about migrating DAVical to Exchange.

They vanished as happens in the way of people with more ambition than budget, but it did get us thinking about how to do Open Source calendar server migration to Exchange or Office 365.

This is made easier because we already have a full-state migration method out of Zimbra into Exchange and Office 365.

Works like this:

Short answer is I'm pretty sure we can do it using the REST implementation we already implemented for Zimbra.

In Zimbra the format to download an ICS to our migration is:

http://SERVER/home/username/calendar?fmt=ics

In DAVical (https://www.davical.org/clients.php) it's

http://SERVER/caldav.php/username/calendar/

The ICS is close enough that it presents no problems, and there is admin access to all accounts.

So we have a decent chance of getting this to work.

Also Zyg's tried it out in the lab and got it to function, but undoubtedly there's a bug or two in there that real-world hardening will discover and squash.

So sites with several hundred users and a willingness to spend part of their test phase in careful mode can feel free to contact us.

DAVical is built on top of PostgreSQL which we read in order to migrate Apple's iCalendar server, but there's no indication that's a superior migration path.  And it represents a little more work so -- nope.