While migrating to Kontact it might come up that a large set of
ics files have to be imported into Kontact. There is a GUI way to do that, but that involves a large number of clicks for each file. Easier is the command line way:
$ ls *.ics | xargs -n 1 konsolekalendar --file ~/.kde/share/apps/korganizer/std.ics --import
Another way is to copy all
ics files to a directory. A new calendar can be created with this new directory which afterwards contains all the data from the
ics files. This calendar can again be exported as one single
ics files which can be easily imported everywhere.