Need Suggestions to Process .ics Text File

I have a few Calendars which I am exporting/importing to a new 
calendaring system. I want to parse down about a dozen of them 
to include only dates since Jan 1, 2014 wherein they presently 
go all the way back to circa 2000, there are a lot of events involved!

The only reasonable approach I can see is to parse them in a 
text editor such as BBEdit, but I find that the .ics files are 
NOT chronologically organized and I'm having trouble seeing a 
good way to automate the finding and selecting of events which I 
want to keep, (or discard) based upon dates. I can understand 
what needs to be done but don't like the apparent complexity of 
doing it.

I'm wondering if anyone on the list has ever tried this and 
developed a good Panorama methodology for it.

Thanks —— Jack