How to Compare Just the Time of a Date in Swift

How do you compare just the time of a Date in Swift?

This is the route I took in the end, which makes it easy to compare just the time of a Date in swift

New Object Time:

class Time: Comparable, Equatable {
init(_ date: Date) {
    //get the current calender
    let calendar = Calendar.current

    //get just the minute and the hour of the day passed to it
    let dateComponents = calendar.dateComponents([.hour, .minute], from: date)

        //calculate the seconds since the beggining of the day for comparisions
        let dateSeconds = dateComponents.hour! * 3600 + dateComponents.minute! * 60

        //set the varibles
        secondsSinceBeginningOfDay = dateSeconds
        hour = dateComponents.hour!
        minute = dateComponents.minute!
    }

    init(_ hour: Int, _ minute: Int) {
        //calculate the seconds since the beggining of the day for comparisions
        let dateSeconds = hour * 3600 + minute * 60

        //set the varibles
        secondsSinceBeginningOfDay = dateSeconds
        self.hour = hour
        self.minute = minute
    }

    var hour : Int
    var minute: Int

    var date: Date {
        //get the current calender
        let calendar = Calendar.current

        //create a new date components.
        var dateComponents = DateComponents()

        dateComponents.hour = hour
        dateComponents.minute = minute

        return calendar.date(byAdding: dateComponents, to: Date())!
    }

    /// the number or seconds since the beggining of the day, this is used for comparisions
    private let secondsSinceBeginningOfDay: Int

    //comparisions so you can compare times
    static func == (lhs: Time, rhs: Time) -> Bool {
        return lhs.secondsSinceBeginningOfDay == rhs.secondsSinceBeginningOfDay
    }

    static func < (lhs: Time, rhs: Time) -> Bool {
        return lhs.secondsSinceBeginningOfDay < rhs.secondsSinceBeginningOfDay
    }

    static func <= (lhs: Time, rhs: Time) -> Bool {
        return lhs.secondsSinceBeginningOfDay <= rhs.secondsSinceBeginningOfDay
    }


    static func >= (lhs: Time, rhs: Time) -> Bool {
        return lhs.secondsSinceBeginningOfDay >= rhs.secondsSinceBeginningOfDay
    }


    static func > (lhs: Time, rhs: Time) -> Bool {
        return lhs.secondsSinceBeginningOfDay > rhs.secondsSinceBeginningOfDay
    }
}

Date Extension for easy access:
//Adds ability to just get the time from a date:

extension Date {
    var time: Time {
        return Time(self)
    }
}

Example:

let firstDate = Date()
let secondDate = firstDate

//Will return true
let timeEqual = firstDate.time == secondDate.time

Compare only time difference in Date objects

You can use Calendar to extract the DateComponents and then combine the day, month, and year from one with the hour, minute, and second of the other into another Date object. Then you can compare the two Date objects that share the same date using the well documented methods.

For example, given date1 and date2, we can calculate date3 with date of date1, but time of date2. We can then compare date1 to this new date3:

let calendar = Calendar.current
let components2 = calendar.dateComponents([.hour, .minute, .second], from: date2)
let date3 = calendar.date(bySettingHour: components2.hour!, minute: components2.minute!, second: components2.second!, of: date1)!

Then, to get the number of minutes between date1 and date3:

let minutes = calendar.dateComponents([.minute], from: date1, to: date3).minute!

Or hours and minutes:

let difference = calendar.dateComponents([.hour, .minute], from: date1, to: date3)
let hours = difference.hour!
let minutes = difference.minute!

Or, if you want to show this to the user, you'd often use DateComponentsFormatter to get a nice, localized string representation:

let formatter = DateComponentsFormatter()
formatter.unitsStyle = .full
formatter.allowedUnits = [.hour, .minute]  // or [.minute]
let string = formatter.string(from: date1, to: date3)!

comparing time without date swift3

Suggestion using DateComponents

Assuming this given array

let times = ["4:30 AM","1:00 PM","3:20 PM","6:40 PM","9:10 PM"]

Create a date formatter matching the format

let formatter = DateFormatter()
formatter.dateFormat = "h:mm a"

Map the time strings to Date and immediately to DateComponents considering only hour and minute

let dateArray = times.map { Calendar.current.dateComponents([.hour, .minute], from:formatter.date(from:$0)!) }

Map this array to the next date from now matching the components respectively

let upcomingDates = dateArray.map { Calendar.current.nextDate(after: Date(), matching: $0, matchingPolicy: .nextTime)!  }

Sort the array ascending, the first item is the date you are looking for
```
let nextDate = upcomingDates.sorted().first!
```
Use the formatter to convert the date back to a time string
```
print(formatter.string(from:nextDate))
```

Comparing Time in ios Swift

Compare the time by ignoring the date component -

func checkTime() -> Bool {

let dateFormatter: DateFormatter = DateFormatter()
dateFormatter.timeZone = TimeZone(abbreviation: "PKT")
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"

let startingSlot = "2000-01-01 08:00:00" //UTC
let endingSlot = "2000-01-01 23:00:00" //UTC

let date = Date()

let date1: Date = dateFormatter.date(from: startingSlot)!
let date2: Date = dateFormatter.date(from: endingSlot)!

let currentTime = 60*Calendar.current.component(.hour, from: date) + Calendar.current.component(.minute, from: date) + (Calendar.current.component(.second, from: date)/60) // in minutes
let time1 = 60*Calendar.current.component(.hour, from: date1) + Calendar.current.component(.minute, from: date1) + (Calendar.current.component(.second, from: date1)/60) // in minutes
let time2 =  60*Calendar.current.component(.hour, from: date2) + Calendar.current.component(.minute, from: date2) + (Calendar.current.component(.second, from: date1)/60) // in minutes

print(currentTime)
print(time1)
print(time2)

if(currentTime >= time1 && currentTime <= time2) {
    return true
} else {
    return false
}

}

Output-

1121

510

1410

true

Swift compare between time

You can use Calendar.current.date(bySetting...) to set the hour/second/minute of an existing date. Then, compare those results.

func getDate() -> Bool {
    let currentDate = Date()
    
    let startDate = Calendar.current.date(bySettingHour: 7, minute: 0, second: 0, of: currentDate)

    let endDate = Calendar.current.date(bySettingHour: 19, minute: 0, second: 0, of: currentDate)

    guard let startDate = startDate, let endDate = endDate else {
      fatalError("Date creation failed ⚠️")
    }
    
    print(startDate < currentDate && currentDate < endDate)
    print(startDate)
    print(endDate)
    print(currentDate)

    return startDate < currentDate && currentDate < endDate
}

Swift 3 - Comparing Date objects

I have tried this snippet (in Xcode 8 Beta 6), and it is working fine.

let date1 = Date()
let date2 = Date().addingTimeInterval(100)

if date1 == date2 { ... }
else if date1 > date2 { ... }
else if date1 < date2 { ... }

Compare DateComponents in swift

You can create dates from the DateComponents and compare them. You can make DateComponents conform to Comparable:

extension DateComponents: Comparable {
    public static func < (lhs: DateComponents, rhs: DateComponents) -> Bool {
        let now = Date()
        let calendar = Calendar.current
        return calendar.date(byAdding: lhs, to: now)! < calendar.date(byAdding: rhs, to: now)!
    }
}

Then you can do those comparisons:

DateComponents(year: 1) > DateComponents(month: 15) // => false
DateComponents(day: 10) > DateComponents(weekOfMonth: 1) // => true

You might also want to make it Equatable:

extension DateComponents: Equatable {
    public static func == (lhs: DateComponents, rhs: DateComponents) -> Bool {
        let now = Date()
        let calendar = Calendar.current
        return calendar.date(byAdding: lhs, to: now)! == calendar.date(byAdding: rhs, to: now)!
    }
}

Disclaimer: This revised answer is using the current date/time as the reference to ensure meaningful comparison of days and months (give that the number of days per month can change). Questions like “are there more than 30 days in a month” only makes sense if the caller supplies a reference date or we use “now” (which is what I’ve done above).

Note, by using “now” as the reference date, then comparisons like “which is greater, 24 hours or 1 day” will now incorporate daylight savings (e.g., depending upon whether your calendar will “spring forward”, “fall back”, or, the vast majority of the time, not change at all).

Swift: Compare date by days

Details

Xcode 11.5 (11E608c), Swift 5.1

Idea

base on usage dateComponents(_:from:to:) function

Solution

import Foundation

extension Date {

    func fullDistance(from date: Date, resultIn component: Calendar.Component, calendar: Calendar = .current) -> Int? {
        calendar.dateComponents([component], from: self, to: date).value(for: component)
    }

    func distance(from date: Date, only component: Calendar.Component, calendar: Calendar = .current) -> Int {
        let days1 = calendar.component(component, from: self)
        let days2 = calendar.component(component, from: date)
        return days1 - days2
    }

    func hasSame(_ component: Calendar.Component, as date: Date) -> Bool {
        distance(from: date, only: component) == 0
    }
}

Full Sample

Do not forget to put here the Solution code (look above)

var dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy hh:mm:ss"
//dateFormatter.timeZone = TimeZone(secondsFromGMT: 0)

let smallerDate = dateFormatter.date(from: "01-01-2012 00:05:01")!
let biggerDate  = dateFormatter.date(from: "03-12-2019 09:30:01")!

print(smallerDate.fullDistance(from: biggerDate, resultIn: .day))       // Optional(2893)
print(biggerDate.fullDistance(from: smallerDate, resultIn: .day))       // Optional(-2893)
print(smallerDate.fullDistance(from: biggerDate, resultIn: .year))      // Optional(7)
print(biggerDate.fullDistance(from: smallerDate, resultIn: .year))      // Optional(7)
print(smallerDate.fullDistance(from: biggerDate, resultIn: .hour))      // Optional(69441)
print(biggerDate.fullDistance(from: smallerDate, resultIn: .hour))      // Optional(-69441)

print(smallerDate.distance(from: biggerDate, only: .day))               // -2
print(biggerDate.distance(from: smallerDate, only: .day))               // 2
print(smallerDate.distance(from: biggerDate, only: .year))              // -7
print(biggerDate.distance(from: smallerDate, only: .year))              // 7
print(smallerDate.distance(from: biggerDate, only: .hour))              // -9
print(biggerDate.distance(from: smallerDate, only: .hour))              // 9

print(smallerDate.hasSame(.day, as: biggerDate))                        // false
print(biggerDate.hasSame(.second, as: smallerDate))                     // true

Comparing NSDates without time component

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