Workflow for Alfred 2 (and 3) to add an event in Calendar.

Just type:

cal [event] at [time][am|pm] [on [date]] [dur] [every] in [location] @[calendar name] alarm [X min|hour|day|month|year]

cal default

at - on - dur - every - in - @ - alarm

When you execute the cal command for the first time, Calendar will pop a dialog like this:

You have to select the default Calendar name that will be used to create new events.

You can change it later typing:

cal default

cal meet my mother at 15:00 on 10/03/2013 in ShoppingM @Personal alarm 0 minute 30 minutes 1 h 8 hours

Create an event, using "Personal" calendar, with 4 sound alarms - at the time of event, 30 minutes before, 1 hour before and 8 hours before.

Or just:

cal some important event at 9pm tomorrow dur 4 hours

Create an event tomorrow from 9pm to 1am

You can omit "at" for "all day event"

cal event at 14 on 21 dur 1 h
cal event at 14 tomorrow alarm 0 m 10 h 5 days 1 month 1 year
cal event at 14 on 21/04 alarm 1 d 5 days
cal event today
cal event tomorrow
cal event at 15 on 28/03/13 dur 4 days
cal event on 25 every year
cal event at 15 every monday
cal event every month
cal event at 15 on 28 in Museum alarm 10 d 2 months
cal event at 11pm on 23
cal event at 10 pm today dur 2 h
cal event at 9pm tomorrow alarm 5 days
cal event at 11 am tomorrow
cal event at 11 tomorrow
cal event at 15 on friday
cal event at 14 on mon
cal event at 2pm on saturday
cal event at 2pm on sat every day