An AppleScript to automatically create a calendar event from an e-mail containing a date and time of the form "March 10, 2015 12:00 - 2:00 PM". Distributed under MIT license (see below)

email to calendar

(*
	Create Calendar event from Message
*)
set theContent to string

-- A subroutine to strip all tags from html
on remove_markup(this_text)
	set copy_flag to true
	set the clean_text to ""
	repeat with this_char in this_text
		set this_char to the contents of this_char
		if this_char is "<" then
			set the copy_flag to false
		else if this_char is ">" then
			set the copy_flag to true
		else if the copy_flag is true then
			set the clean_text to the clean_text & this_char as string
		end if
	end repeat
	return the clean_text
end remove_markup

tell application "Microsoft Outlook"
	
-- get the currently selected message or messages
	set selectedMessages to current messages
	
-- if there are no messages selected, warn the user and then quit
	if selectedMessages is {} then
		display dialog "Please select a message first and then run this script." with icon 1
		return
	end if
	
	repeat with theMessage in selectedMessages
		
-- get the information from the message, and store it in variables
		set theName to subject of theMessage
		set theCategory to category of theMessage
		set theContent to content of theMessage

-- Strip out all the newlines and returns, so the text can be piped into echo
		set AppleScript's text item delimiters to {return & linefeed, return, linefeed, character id 8233, character id 8232, character id 40, character id 41}
		set newText to text items of theContent
		set AppleScript's text item delimiters to {" "}
		set newText to newText as text

-- Get rid of all the html tags
		set newText to my remove_markup(newText)
		"echo " & quoted form of newText & " | grep -o .*"
		set theMonth to do shell script "printf " & quoted form of newText & " | grep -o \"January\\|February\\|March\\|April\\|May\\|June\\|July\\|August\\|September\\|October\\|Novermber\\|December\" | head -n1"
		set theDay to do shell script "echo " & quoted form of newText & " | grep -o \"" & theMonth & " [0-9]\\{1,2\\}\" | grep -o \"[0-9]\\{1,2\\}\""
		set theYear to do shell script "echo " & quoted form of newText & " | grep -o \"2015\\|2016\\|2017\" | head -n1"
--If no year is specified, assume it's for the current year
		if (length of theYear) = 0 then
			set theYear to year of (current date)
		end if
		
		set startTime to do shell script "printf " & quoted form of newText & " | grep -o \"[0-9]\\{1,2\\}:[0-9]\\{1,2\\}\" | head -n1"
		set endTime to do shell script "printf " & quoted form of newText & " | grep -o \"[0-9]\\{1,2\\}:[0-9]\\{1,2\\}\" | tail -n1"
		set ampm to do shell script "echo " & quoted form of newText & " | grep -o \"AM\\|PM\\|pm\" | head -n1"
		
-- create a new event with the information from the task
		set startDate to date (theMonth & " " & theDay & ", " & theYear & " " & startTime & " " & ampm) as date
		set endDate to date (theMonth & " " & theDay & ", " & theYear & " " & endTime & " " & ampm) as date
		set newEvent to make new calendar event with properties {subject:theName, category:theCategory, content:theContent, start time:startDate, end time:endDate}
		
	end repeat
end tell

The MIT License (MIT)

Copyright (c) 2015 Ben Chartoff

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.