Comment 168 for bug 849416

@Eliot - I think for most users that would be a preferable solution - for those who want to avoid Lightning entirely.

For my own purposes I finally navigated the complex steps of integrating it so Lightning uses iCal - no mere mortal will ever succeed with those steps - but until that point one of the worst features of TB was failure to integrate with the same calendar used for all other functions on OSX, and given how much calendars are integrated into people's workflow these days must be a significant driver away from TB and towards Apple's Mail.