[Evolution] sharing evolution calendars

[michael <cs networkingnewsletter org uk>]

I've looked before and not found the solution so am asking again in case
I've missed something!

I run Evolution at home and at work and wish to have a single calendar.
What's the easiest way of doing this? I know how to copy .ICS and import
but that's too much of a chore and liable to mess-ups.

Ideally I'd also want to share with a third machine which is MacOS with
iCal.

Thanks, M