drawViewHierarchyFromRect fails to work.

calendarImage.playground

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

import UIKit

let view = UIView(frame: CGRect(x: 0, y: 0, width: 30, height: 30))

if let calendarIcon = UIImage(named: "Events") {
    let calendarView = UIImageView(image: calendarIcon)
    view.addSubview(calendarView)
}

let date = NSDate(timeIntervalSinceNow: 4*30*24*60*60)
let dateFormatter = NSDateFormatter()

// Create the month

dateFormatter.dateFormat = "MMM"
let month = dateFormatter.stringFromDate(date).uppercaseString

let monthLabel = UILabel(frame: CGRect(x: 8, y: 4, width: 14, height: 4))
monthLabel.text = month
monthLabel.font = UIFont.boldSystemFontOfSize(6)
monthLabel.textAlignment = .Center
monthLabel.textColor = UIColor.whiteColor()
view.addSubview(monthLabel)

// Create the day number

dateFormatter.dateFormat = "dd"
let day = dateFormatter.stringFromDate(date)

let numberLabel = UILabel(frame: CGRect(x: 4, y: 9, width: 22, height: 17))
numberLabel.text = day
numberLabel.font = UIFont.boldSystemFontOfSize(14)
numberLabel.textAlignment = .Center
view.addSubview(numberLabel)

println("Everything seems to be working fine.")

UIGraphicsBeginImageContextWithOptions(view.bounds.size, false, 2)
//view.drawViewHierarchyInRect(view.bounds, afterScreenUpdates: true)
view.layer.renderInContext(UIGraphicsGetCurrentContext()) // Interestingly enough, this does work :/
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

let imageView = UIImageView(image: image)
println("However, here nothing updates anymore.")

CalendarTabImage.swift

extension UIImage
{
    class func calendarTabImageWithCurrentDate() -> UIImage
    {
        return calendarTabImageWithDate(NSDate())
    }
    
    class func calendarTabImageWithDate(date: NSDate) -> UIImage
    {
        let dateFormatter = NSDateFormatter()
        let view = UIView(frame: CGRect(x: 0, y: 0, width: 30, height: 30))
        
        let calendarView = UIImageView()
        calendarView.frame = CGRect(x: 0, y: 0, width: 30, height: 30)
        if let calendarImage = UIImage(named: "EventsTabIcon") {
            calendarView.image = calendarImage
        }
        view.addSubview(calendarView)
        
        // Create the month
        
        dateFormatter.dateFormat = "MMM"
        let month = dateFormatter.stringFromDate(date).uppercaseString
        
        let monthLabel = UILabel(frame: CGRect(x: 8, y: 4, width: 14, height: 4))
        monthLabel.text = month
        monthLabel.font = UIFont.boldSystemFontOfSize(6)
        monthLabel.textAlignment = .Center
        monthLabel.textColor = UIColor.whiteColor()
        view.addSubview(monthLabel)
        
        // Create the day number
        
        dateFormatter.dateFormat = "dd"
        let day = dateFormatter.stringFromDate(date)
        
        let numberLabel = UILabel(frame: CGRect(x: 4, y: 9, width: 22, height: 17))
        numberLabel.text = day
        numberLabel.font = UIFont.boldSystemFontOfSize(14)
        numberLabel.textAlignment = .Center
        view.addSubview(numberLabel)
        
        UIGraphicsBeginImageContextWithOptions(view.bounds.size, false, UIScreen.mainScreen().scale)
        //view.drawViewHierarchyInRect(view.bounds, afterScreenUpdates: true)
        view.layer.renderInContext(UIGraphicsGetCurrentContext())
        let result = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        return result
    }
}