Comparing NSDates without time component

There are several useful methods in NSCalendar in iOS 8.0+:

startOfDayForDate, isDateInToday, isDateInYesterday, isDateInTomorrow

And even to compare days:

func isDate(date1: NSDate!, inSameDayAsDate date2: NSDate!) -> Bool

To ignore the time element you can use this:

var toDay = Calendar.current.startOfDay(for: Date())

But, if you have to support also iOS 7, you can always write an extension

extension NSCalendar {
    func myStartOfDayForDate(date: NSDate!) -> NSDate!
    {
        let systemVersion:NSString = UIDevice.currentDevice().systemVersion
        if systemVersion.floatValue >= 8.0 {
            return self.startOfDayForDate(date)
        } else {
            return self.dateFromComponents(self.components(.CalendarUnitYear | .CalendarUnitMonth | .CalendarUnitDay, fromDate: date))
        }
    }
}

Use this Calendar function to compare dates in iOS 8.0+

func compare(_ date1: Date, to date2: Date, toGranularity component: Calendar.Component) -> ComparisonResult

passing .day as the unit

Use this function as follows:

let now = Date()
// "Sep 23, 2015, 10:26 AM"
let olderDate = Date(timeIntervalSinceNow: -10000)
// "Sep 23, 2015, 7:40 AM"

var order = Calendar.current.compare(now, to: olderDate, toGranularity: .hour)

switch order {
case .orderedDescending:
    print("DESCENDING")
case .orderedAscending:
    print("ASCENDING")
case .orderedSame:
    print("SAME")
}

// Compare to hour: DESCENDING

var order = Calendar.current.compare(now, to: olderDate, toGranularity: .day)


switch order {
case .orderedDescending:
    print("DESCENDING")
case .orderedAscending:
    print("ASCENDING")
case .orderedSame:
    print("SAME")
}

// Compare to day: SAME