I'm using NXLog to convert IIS logs to JSON for loading into a log analyzing app. I would like to schedule cleaning up the IIS logs that are older than 14 days but I can't figure out how to get a DateTime 14 days in the past. The following works but will obviously remove everything older than now. Is it possible to do something like "now().addDays(-1)" or "now() - days(14)"? I've tried "now() - 1209600" (subtracting 14 days as seconds) but it doesn't seem to do anything, no messages in nxlog.log either.