So here's the situation: my company has been in business for a while and has had several sysadmins of varying levels of competence. Now it's my turn. I have a CalDAV server set up for users and it integrates nicely in lightning, users can send meeting invites locally and externally. One user (the boss) has three "work" calendars he would like merged into the one CalDAV-enabled calendar I have set up for him. I know that I can export and import calendars in Lightning, which is great except then Thunderbird will send an email invite to ever person on those meeting lists again. Obviously I do not want this to happen. Question: how can I move all events on one Lightning calendar to another one without sending invites to every person in the last 3 years?