3 0 0 * * * ikiwiki-calendar ~/ikiwiki.setup "posts/* and !*/Discussion"
7 0 0 * * * ikiwiki-calendar ~/ikiwiki.setup 'posts/* and !*/Discussion'
9 I ran into (for me) unexpected behaviour with double quotes, since when I tried it in the interactive shell, the "!" made it fail ([history expansion](http://mywiki.wooledge.org/BashPitfalls#echo_.22Hello_World.21.22)). I thought "aha, it should be escaped!", did so, and did not get any error messages, but it no longer functioned as intended (as per the earlier linked page).
11 The latter line will work everywhere, not just in environments without history expansion. I think trying a command manually before putting it into crontab is common, and this would avoid the possible user issue I ran into.