title: calculating recurring events in ObjC (iPhone)
body: <p>I'm looking for a library that would let me handle recurring events in ObjC on iPhone. I'm writing a task management app that needs to handle scheduled (monthly/weekly/etc.) tasks, and I need to check which tasks should have an occurrence on a given day. Basically, I need something like <a href="http://runt.rubyforge.org/" rel="nofollow">runt</a> or <a href="http://seejohncode.com/ice_cube/" rel="nofollow">ice_cube</a>, but in ObjC.</p>
  
  <p>I looked at Apple's EventKit framework, which seems to provide the functionality I need, but the problem is that it only works with user's own calendars in the Calendar app. I need something that would let me work on internal data stored only inside the application. I don't see any way to create an internal in-app calendar in EventKit, and I don't want to mess with user's main calendar.</p>
  
  <p>There's also the Google Data library for ObjC, which also does something similar, but as far as I can tell, it doesn't do any such calculations on the client side, the recurrence rules you set are only used for passing them to the server as URL parameters, and I need to be able to use it offline.</p>
  
  <p>Does anyone know if such lib exists? I could code it myself, but I'm afraid that this might be, as someone said here on SO, "embracing insanity"...</p>