turn the crappy date strings from google calendar xml into Moment objects

googleCalDateParser.js

var moment = require('moment-timezone');

module.exports = function(input){
  var eventTimes = {
    start: false,
    end: false
  };
  var a,b;

  var splitMarker = input.indexOf('to');
  if (splitMarker > -1) {
    a = input.slice(0,splitMarker - 1);
    b = input.slice(splitMarker + 3);

    // now see if it's like 'Fri Dec 5, 2014 4pm to 6pm PST' or 'Fri
    // Oct 17, 2014 4pm to Fri Oct 17, 2014 6pm PDT' by looking at the
    // first character of the 'b' string
    if ( /[0-9]/.test(b.charAt(0)) ) {
      var n = a.length;
      // walk backwards through the 'a' string until we find a space
      while (a.charAt(n) !== ' '){
        n--;
      }
      // then add the date information from 'a' to the 'b' string
      b = a.slice(0,n+1) + b;
    }
  }
  else {
    a = input;
  }

  // we'll use this to cut off anything after the last 'am' or 'pm'
  var timeZone = /(.*m)[^m]*/;
  if (a) {
    a = a.replace(timeZone, "$1");
    // http://momentjs.com/docs/#/parsing/string-format/
    // http://momentjs.com/timezone/docs/#/using-timezones/parsing-in-zone/
    a = moment.tz(a, "ddd MMM DD, YYYY ha", "America/Los_Angeles");
  }
  if (b) {
    b = b.replace(timeZone, "$1");
    b = moment.tz(b, "ddd MMM DD, YYYY ha", "America/Los_Angeles");
  }

  eventTimes.start = a;
  eventTimes.end = b;

  return eventTimes;
};

test.js

var parser = function(){
  // the sort of date strings you get from google calendar xml
  var tests = ['Wed Sep 24, 2014 10am to 10am PDT',
               'Fri Dec 5, 2014 4pm to 6pm PST',
               'Fri Oct 17, 2014 4pm to Fri Oct 17, 2014 6pm PDT',
               'Thu Sep 11, 2014'
              ];
  var parse = require('./googleCalDateParser.js');

  var j = tests.length;
  while (j--){
    console.log(parse(tests[j]));
  }
};

parser();