Comparing dates with Foundation

This recipe will focus on one area of Foundation that is very widely used, that is, date and time manipulation and formatting.

We will create a function that determines how long there is until Christmas and returns this information as a string that can be displayed to a user.

Getting ready

Create a new iOS playground and import the Foundation framework at the top of the playground:

import Foundation

How to do it...

Let's create a function that will return a string telling us how long there is until Christmas that we can then print:

1. Define the function:

func howLongUntilChristmas() -> String {

}

2. Within the function, get the current calendar and time zone:

let calendar = Calendar.current
let timeZone = TimeZone.current

3. Get the current date and time and use the calendar to get the current year:

let now = Date()
let yearOfNextChristmas = calendar.component(.year, from: now)

4. Define date components that correspond to midnight on Christmas Day:

var...