To follow up on last week’s item about parsing the kinds of dates and times that people actually write, Google Calendar’s Quick Add feature looks like the clear winner. Here’s a test page with expressions like:

Third Saturday of Every Month, 10 - 11:30 am

Let’s try the Chronic module from Ruby: 

irb(main):007:0> Chronic.parse('Third Saturday of Every Month, 10 - 11:30 am')
=> nil

No joy.

As David French pointed out, Google Calendar’s Quick Add gets this right. Or anyway, close enough. There seems to be a small bug that pokes an instance of the event into today’s slot, whether or not today is a 3rd Saturday. But otherwise it works great.

There are tougher challenges on that test page, like:

9:00 am - 1:30 pm, North Conference Room 1
April: April 5 and 12
May: May 3 and 10
June: June 7 and 14

I doubt think anything we’ve mentioned so far can touch that, though I’d be happy to be proven wrong.

Meanwhile, the ability to capture recurring events like ‘Third Saturday of Every Month, 10 - 11:30 am’ for my aggregated community calendar has raised a new question. When I use Google Calendar for this purpose, its iCal export doesn’t enumerate the series, it defines a rule: 

LOCATION:Cheshire Medical Center
RRULE:FREQ=MONTHLY;INTERVAL=1;BYDAY=3SA;WKST=MO

When I pull that event into elmcity.info/events, the RRULE (recurrence rule) only fires once each time the feed is fetched. And that’s fine. I don’t necessarily want to see these recurring events on the the calendar into the far future.

But while I can syndicate these events directly from Google Calendar into elmcity.info, I would rather route them through Eventful.com. The reason is social not technical. Although I’m herding almost all these events into my aggregator for the time being, I want their rightful owners to claim them at some point and take care for them thereafter. Eventful is better suited for the kind of commons-based peer production I’m hoping to encourage.

But, I don’t see how to inject dynamic rules, rather than static events, into Eventful. You could run the rule yourself, then poke the generated events into Eventful, but that’d create maintenance woes when events are rescheduled, modified, or cancelled. I’d rather syndicate the rule than the data.