Swift date formatting

DeathToTimezones.swift

//: Playground - noun: a place where people can play

import UIKit

/// We're working with appointments.
/// So I get this string from the server and in some places I need to display it in the users local timezone and in other places I need to display it as the time and date that it was booked

var serverTimeString = "2017-03-21T19:00:00-07:00"

let localisedDateFormatter = DateFormatter()
localisedDateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"

// Displays as March 22nd, 2am (GMT) - CORRECT
var date = localisedDateFormatter.date(from: serverTimeString)

// TO DO: Output date as March 21st, 7pm.
// ??

Could likely tidy it up. I've used regex and timezone calculations to try and catch any timezone not just -7 hours