need help choosing calendar environment

[Eric S. Johansson]

I'm on a Windows laptop
she's on Breezy

I'm on all sorts of different networks (network tramp :-)
she's wired into the home network

We both need access to the calendar at any time, on or even off 
network(local copy).

The calendars should synchronize whenever my little laptop can reach its 
home network.  Synchronization can be manual.

no PHP or webdav (please)

Any suggestions for a calendar?

thanks