Related
I have two Date Objects:
2017-01-13 11:40:17 +0000
2016-03-15 10:22:14 +0000
I need to compare just the time of these values and ignore the date
example: 12:00am and 12:01am, 12:01 is later so (12:01am > 12:00am) == true
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
Much simpler than accepted answer:
SWIFT 4
// date1 and date2 are the dates you want to compare
let calendar = Calendar.current
var newDate = Date(TimeIntervalSinceReferenceDate: 0) // Initiates date at 2001-01-01 00:00:00 +0000
var newDate1 = Date(TimeIntervalSinceReferenceDate: 0) // Same as above
// Recieving the components from the dates you want to compare
let newDateComponents = calendar.dateComponents([.hour, .minute], from: date1)!
let newDate1Components = calendar.dateComponents([.hour, .minute], from: date2)!
// Adding those components
newDate = calendar.date(byAdding: newDateComponents, to: newDate)
newDate1 = calendar.date(byAdding: newDate1Components, to: newDate1)
My approach would be to use Calendar to make them Date objects with the same day and then comparing them using for example timeIntervalSinceReferenceDate.
Another, cleaner (but most likely with more lines of resulting code) would be to create extension for Date called secondsFromBeginningOfTheDay() -> TimeInterval and then comparing the resulting double values.
Example based on the second approach:
// Creating Date from String
let textDate1 = "2017-01-13T12:21:00-0800"
let textDate2 = "2016-03-06T20:12:05-0900"
let dateFormatter: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZ"
formatter.timeZone = TimeZone.current
return formatter
} ()
// Dates used for the comparison
let date1 = dateFormatter.date(from: textDate1)
let date2 = dateFormatter.date(from: textDate2)
// Date extensions
extension Date {
func secondsFromBeginningOfTheDay() -> TimeInterval {
let calendar = Calendar.current
// omitting fractions of seconds for simplicity
let dateComponents = calendar.dateComponents([.hour, .minute, .second], from: self)
let dateSeconds = dateComponents.hour! * 3600 + dateComponents.minute! * 60 + dateComponents.second!
return TimeInterval(dateSeconds)
}
// Interval between two times of the day in seconds
func timeOfDayInterval(toDate date: Date) -> TimeInterval {
let date1Seconds = self.secondsFromBeginningOfTheDay()
let date2Seconds = date.secondsFromBeginningOfTheDay()
return date2Seconds - date1Seconds
}
}
if let date1 = date1, let date2 = date2 {
let diff = date1.timeOfDayInterval(toDate: date2)
// as text
if diff > 0 {
print("Time of the day in the second date is greater")
} else if diff < 0 {
print("Time of the day in the first date is greater")
} else {
print("Times of the day in both dates are equal")
}
// show interval as as H M S
let timeIntervalFormatter = DateComponentsFormatter()
timeIntervalFormatter.unitsStyle = .abbreviated
timeIntervalFormatter.allowedUnits = [.hour, .minute, .second]
print("Difference between times since midnight is", timeIntervalFormatter.string(from: diff) ?? "n/a")
}
// Output:
// Time of the day in the second date is greater
// Difference between times since midnight is 8h 51m 5s
My solution for comparing two times of day while ignoring the date:
let date1 = some time as a date
let date2 = some other time as a date
let time1 = 60*Calendar.current.component(.hour, from: date1!) + Calendar.current.component(.minute, from: date1!)
let time2 = 60*Calendar.current.component(.hour, from: date2!) + Calendar.current.component(.minute, from: date2!)
Now you can compare the integers time1 and time2 without regard to the day. You could add the seconds/60 if you need more precision.
This code works, check it easily in playground
let s1 = "22:31"
let s2 = "14:31"
let f = DateFormatter()
f.dateFormat = "HH:mm"
f.date(from: s1)! //"Jan 1, 2000 at 10:31 PM"
f.date(from: s2)! //"Jan 1, 2000 at 2:31 PM"
f.date(from: s1)! > f.date(from: s2)! // true
There's no standard type for a time-of-day. A reasonable type to start with is just a tuple:
typealias TimeOfDay = (hour: Int, minute: Int, second: Int)
To create these TimeOfDay values, you'll need a Calendar. By default, a Calendar uses the device's system-wide time zone. If you don't want that, set the Calendar's time zone explicitly. Example:
var calendar = Calendar.autoupdatingCurrent
calendar.timeZone = TimeZone(abbreviation: "UTC")!
Now you can use a DateFormatter to convert strings to Dates (if necessary), and then use calendar to extract the time-of-day components from the Dates:
let strings: [String] = ["2017-01-13 11:40:17 +0000", "2016-03-15 10:22:14 +0000"]
let parser = DateFormatter()
parser.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
let timesOfDay: [TimeOfDay] = strings.map({ (string) -> TimeOfDay in
let components = calendar.dateComponents([.hour, .minute, .second], from: parser.date(from: string)!)
return (hour: components.hour!, minute: components.minute!, second: components.second!)
})
Swift.print(timesOfDay)
// Output: [(11, 40, 17), (10, 22, 14)]
Finally, you can compare these TimeOfDay values. Swift comes with standard comparison operators for tuples whose elements are Comparable, so this TimeOfDay type qualifies. You can just say this:
if timesOfDay[0] < timesOfDay[1] {
Swift.print("date[0] comes first")
} else if timesOfDay[0] == timesOfDay[1] {
Swift.print("times are equal")
} else {
Swift.print("date[1] comes first")
}
Let say we got two dates in string format:
// "2017-01-13 11:40:17 +0000"
// "2016-03-15 10:22:14 +0000"
We need to convert this strings to Date format, we create DateFormatter() and set the format ("yyyy-MM-dd' 'HH:mm:ssZ") it gonna convert
//date formatter converts string to date in our case
let firstDateFormatter = DateFormatter()
firstDateFormatter.dateFormat = "yyyy-MM-dd' 'HH:mm:ssZ"
Now we can get our date from string to Date format
//convert string to dates
if let date1 = firstDateFormatter.date(from: "2017-01-13 09:40:17 +0000"),
let date2 = firstDateFormatter.date(from: "2016-03-15 10:22:14 +0000") {
What we want is to compare only Hours and Minutes. So change dateformat to "HH:mm"
//we ve got the dates, now switch dateformat for other job
firstDateFormatter.dateFormat = "HH:mm"
Now get the string value from our date, that only contain "HH:mm"
// convert date to string ( part of string we want to compare )
let HHmmDate1 = firstDateFormatter.string(from: date1) //"17:40"
let HHmmDate2 = firstDateFormatter.string(from: date2) //"18:22"
Final step is to get date from our "HH:mm" values, let say we ask DateFormatter to give us a date, based on time only, in our case "17:40" and "18:22". DateFormatter will put some values for dates, so we get Jan 1, 2000 automatically for both dates, but it will get the time we provide.
//produce "default" dates with desired HH:mm
//default means same date, but time is different
let HH1 = firstDateFormatter.date(from: HHmmDate1) //"Jan 1, 2000 at 5:40 PM"
let HH2 = firstDateFormatter.date(from: HHmmDate2) //"Jan 1, 2000 at 6:22 PM"
Now we could easily compare dates
//compare
HH1! > HH2!
}
There are many options to compare dates with Calendar also
This is very simple in Swift if you use Swifter Swift
date1.day = 1
date1.month = 1
date1.year = 2000
date2.day = 1
date2.month = 1
date2.year = 2000
now you can use >,<,== operators on date1 and date2 to compare just the time components.
edit - you could do this your self by extending the date class, for example swifter-swift does the bellow for the day component.
public var day: Int {
get {
return Calendar.current.component(.day, from: self)
}
set {
let allowedRange = Calendar.current.range(of: .day, in: .month, for: self)!
guard allowedRange.contains(newValue) else { return }
let currentDay = Calendar.current.component(.day, from: self)
let daysToAdd = newValue - currentDay
if let date = Calendar.current.date(byAdding: .day, value: daysToAdd, to: self) {
self = date
}
}
}
I am currently making a scheduling feature for my application. I have a view where a user is able to select what days of the week they will be available for. Now, I am looking for a way to generate an array of dates for the given weekdays for the upcoming month.
In other words, if the user selects that they will be available on Monday, the function needs to return all dates that satisfy the given predicament for the month ahead (4 date objects).
Here's what I have tried but it doesn't seem to work:
var masterSchedule = [WorkDay(weekDay: 1, startTime: 8, endTime: 16, busyHours: []), WorkDay(weekDay: 4, startTime: 8, endTime: 16, busyHours: [])]
func getDates() {
for workDay in masterSchedule {
var components = DateComponents()
components.weekday = workDay.weekDay
components.year = 2021
components.month = 8
let date = Calendar.current.date(from: components) ?? Date()
availableDays.append(date)
}
}
For some reason, the output returns 2 same dates of 2021-07-31 23:00:00 +0000.
Can someone help me?
Here's an example that prints all the Mondays in October
import UIKit
import SwiftUI
import PlaygroundSupport
let calendar = Calendar.current
let formatter = DateFormatter()
formatter.dateStyle = .short
let firstOfOctober = formatter.date(from: "10/1/2021")!
if let interval = calendar.dateInterval(of: .month, for: firstOfOctober) {
let mondays = DateComponents(weekday: 2)
calendar.enumerateDates(startingAfter: firstOfOctober,
matching: mondays, matchingPolicy: .previousTimePreservingSmallerComponents) {
date, exactMatch, stopLooking in
if let date = date {
if date < interval.end {
print(formatter.string(from: date))
} else {
stopLooking = true
}
}
}
}
I need to compare two Date object to get the day difference between them, for example: 10/10 compares with today 10/7 will be 3, but the Date object returned to me from server is not aligned with the current time. There will be a few minutes difference which results in 10/10 being 2 days ahead of 10/7 because of the delay
I found a line of code that can give me a Date object of the current time, but I want to convert an existing Date object from somewhere else, how do I do it?
let today = Calendar.current.date(bySettingHour: 0, minute: 0, second: 0, of: Date())!
e.g. 2020-10-08 16:08:57.259580+0000 I want it to be 2020-10-08 00:00:00 +0000 something like this
Don’t use midnight. Just parse your date string first. For calendrical calculations you should always use noon. First create a custom date format to parse your date string properly.
extension Formatter {
static let iso8601: DateFormatter = {
let formatter = DateFormatter()
formatter.locale = .init(identifier: "en_US_POSIX")
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss.SSSSSSxx"
formatter.timeZone = TimeZone(secondsFromGMT: 0)
return formatter
}()
}
Then create a helper to convert your date to noon time and another one to calculate the days between two dates and set them to noon:
extension Date {
var noon: Date {
Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: self)!
}
func days(from date: Date) -> Int {
Calendar.current.dateComponents([.day], from: date.noon, to: noon).day!
}
var daysFromToday: Int { days(from: Date()) }
}
Playground testing:
let dateString = "2020-10-08 16:08:57.259580+0000"
let now = Date() // "Oct 8, 2020 at 5:56 AM"
print(Formatter.iso8601.string(from: now)) // "2020-10-08 08:56:46.179000+0000\n"
if let date = Formatter.iso8601.date(from: dateString) { // "Oct 8, 2020 at 1:08 PM"
let days = Date().days(from: date) // 0
}
let dateString = "2020-10-10 16:08:57.259580+0000"
if let date = Formatter.iso8601.date(from: dateString) {
let days = date.daysFromToday // 2
}
I currently use the following code to return an array of dates for every single day between two dates, including today's date and the last date itself. This works great.
However, how would I go about modifying what I'm already doing in
order to do the same exact thing otherwise, but instead return an
array of the date of every Friday between the dates? For example, if the function was called on Wed Oct 23rd 2019 to return every Friday until November 10th, the first date would be Fri the 25th, Nov 1st, and then Nov 8th.
How would I do the same thing as above but for the 1st of every month? If I called the function on Wed Oct 23rd 2019 to return the first of every month until December 16th. The array should have Nov 1st and Dec 1st in it.
func dates(for date: String) -> [String] {
// first get the endDate
guard var endDate = Formatter.date.date(from: date) else { return [] }
// for calendrical calculations you should use noon time
endDate = Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: endDate)!
// lets get todays noon time to start
var date = Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: Date())!
var dates: [String] = []
// while date less than or equal to end date
while date <= endDate {
// add the formatted date to the array
dates.append( Formatter.date.string(from: date))
// increment the date by one day
date = Calendar.current.date(byAdding: .day, value: 1, to: date)!
}
return dates
}
You just need to add a weekday parameter to your method and check if the weekday of the date inside the loop before adding it to your array:
extension Formatter {
static let date = DateFormatter()
}
func dates(for date: String, weekday: Int? = nil) -> [String] {
Formatter.date.locale = Locale(identifier: "en_US_POSIX")
Formatter.date.dateFormat = "yyyy-MM-dd"
// first get the endDate
guard var endDate = Formatter.date.date(from: date) else { return [] }
// for calendrical calculations you should use noon time
endDate = Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: endDate)!
// lets get todays noon time to start
var date = Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: Date())!
var dates: [String] = []
// while date less than or equal to end date
while date <= endDate {
if weekday == nil {
dates.append(Formatter.date.string(from: date))
date = Calendar.current.date(byAdding: .day, value: 1, to: date)!
} else if let weekday = weekday, Calendar.current.component(.weekday, from: date) == weekday {
// add the formatted date to the array
dates.append(Formatter.date.string(from: date))
date = Calendar.current.date(byAdding: .weekOfYear, value: 1, to: date)!
} else {
date = Calendar.current.date(byAdding: .day, value: 1, to: date)!
}
}
return dates
}
dates(for: "2019-12-25") // ["2019-10-23", "2019-10-24", "2019-10-25", "2019-10-26", "2019-10-27", "2019-10-28", "2019-10-29", "2019-10-30", "2019-10-31", "2019-11-01", "2019-11-02", "2019-11-03", "2019-11-04", "2019-11-05", "2019-11-06", "2019-11-07", "2019-11-08", "2019-11-09", "2019-11-10", "2019-11-11", "2019-11-12", "2019-11-13", "2019-11-14", "2019-11-15", "2019-11-16", "2019-11-17", "2019-11-18", "2019-11-19", "2019-11-20", "2019-11-21", "2019-11-22", "2019-11-23", "2019-11-24", "2019-11-25", "2019-11-26", "2019-11-27", "2019-11-28", "2019-11-29", "2019-11-30", "2019-12-01", "2019-12-02", "2019-12-03", "2019-12-04", "2019-12-05", "2019-12-06", "2019-12-07", "2019-12-08", "2019-12-09", "2019-12-10", "2019-12-11", "2019-12-12", "2019-12-13", "2019-12-14", "2019-12-15", "2019-12-16", "2019-12-17", "2019-12-18", "2019-12-19", "2019-12-20", "2019-12-21", "2019-12-22", "2019-12-23", "2019-12-24", "2019-12-25"]
dates(for: "2019-12-25", weekday: 6) // ["2019-10-25", "2019-11-01", "2019-11-08", "2019-11-15", "2019-11-22", "2019-11-29", "2019-12-06", "2019-12-13", "2019-12-20"]
func firstDayOfTheMonth(until date: String) -> [String] {
Formatter.date.locale = Locale(identifier: "en_US_POSIX")
Formatter.date.dateFormat = "yyyy-MM-dd"
guard let endDate = Formatter.date.date(from: date) else { return [] }
var date = Date()
var dates: [String] = []
// while date less than or equal to end date
while let firstDayOfTheMonth = Calendar.current.nextDate(after: date, matching: .init(day: 1), matchingPolicy: .nextTime), firstDayOfTheMonth <= endDate {
dates.append(Formatter.date.string(from: firstDayOfTheMonth))
date = firstDayOfTheMonth
}
return dates
}
firstDayOfTheMonth(until: "2019-12-25") // ["2019-11-01", "2019-12-01"]
You can get the weekday for any day of the week with:
let weekDayIndex = Calendar.current.component(.weekday, from: Date())
Friday happens to be day 5. You can get the name of any day with:
print(Calendar.current.weekdaySymbols[weekDayIndex])
So just loop over all of your dates and filter out anything where the weekday is not 5 and you have your answer:
func fridays(in dates: [Date]) {
dates.filter { Calendar.current.component(.weekday, from: $0) == 5 }
}
I have two Date Objects:
2017-01-13 11:40:17 +0000
2016-03-15 10:22:14 +0000
I need to compare just the time of these values and ignore the date
example: 12:00am and 12:01am, 12:01 is later so (12:01am > 12:00am) == true
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
Much simpler than accepted answer:
SWIFT 4
// date1 and date2 are the dates you want to compare
let calendar = Calendar.current
var newDate = Date(TimeIntervalSinceReferenceDate: 0) // Initiates date at 2001-01-01 00:00:00 +0000
var newDate1 = Date(TimeIntervalSinceReferenceDate: 0) // Same as above
// Recieving the components from the dates you want to compare
let newDateComponents = calendar.dateComponents([.hour, .minute], from: date1)!
let newDate1Components = calendar.dateComponents([.hour, .minute], from: date2)!
// Adding those components
newDate = calendar.date(byAdding: newDateComponents, to: newDate)
newDate1 = calendar.date(byAdding: newDate1Components, to: newDate1)
My approach would be to use Calendar to make them Date objects with the same day and then comparing them using for example timeIntervalSinceReferenceDate.
Another, cleaner (but most likely with more lines of resulting code) would be to create extension for Date called secondsFromBeginningOfTheDay() -> TimeInterval and then comparing the resulting double values.
Example based on the second approach:
// Creating Date from String
let textDate1 = "2017-01-13T12:21:00-0800"
let textDate2 = "2016-03-06T20:12:05-0900"
let dateFormatter: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZ"
formatter.timeZone = TimeZone.current
return formatter
} ()
// Dates used for the comparison
let date1 = dateFormatter.date(from: textDate1)
let date2 = dateFormatter.date(from: textDate2)
// Date extensions
extension Date {
func secondsFromBeginningOfTheDay() -> TimeInterval {
let calendar = Calendar.current
// omitting fractions of seconds for simplicity
let dateComponents = calendar.dateComponents([.hour, .minute, .second], from: self)
let dateSeconds = dateComponents.hour! * 3600 + dateComponents.minute! * 60 + dateComponents.second!
return TimeInterval(dateSeconds)
}
// Interval between two times of the day in seconds
func timeOfDayInterval(toDate date: Date) -> TimeInterval {
let date1Seconds = self.secondsFromBeginningOfTheDay()
let date2Seconds = date.secondsFromBeginningOfTheDay()
return date2Seconds - date1Seconds
}
}
if let date1 = date1, let date2 = date2 {
let diff = date1.timeOfDayInterval(toDate: date2)
// as text
if diff > 0 {
print("Time of the day in the second date is greater")
} else if diff < 0 {
print("Time of the day in the first date is greater")
} else {
print("Times of the day in both dates are equal")
}
// show interval as as H M S
let timeIntervalFormatter = DateComponentsFormatter()
timeIntervalFormatter.unitsStyle = .abbreviated
timeIntervalFormatter.allowedUnits = [.hour, .minute, .second]
print("Difference between times since midnight is", timeIntervalFormatter.string(from: diff) ?? "n/a")
}
// Output:
// Time of the day in the second date is greater
// Difference between times since midnight is 8h 51m 5s
My solution for comparing two times of day while ignoring the date:
let date1 = some time as a date
let date2 = some other time as a date
let time1 = 60*Calendar.current.component(.hour, from: date1!) + Calendar.current.component(.minute, from: date1!)
let time2 = 60*Calendar.current.component(.hour, from: date2!) + Calendar.current.component(.minute, from: date2!)
Now you can compare the integers time1 and time2 without regard to the day. You could add the seconds/60 if you need more precision.
This code works, check it easily in playground
let s1 = "22:31"
let s2 = "14:31"
let f = DateFormatter()
f.dateFormat = "HH:mm"
f.date(from: s1)! //"Jan 1, 2000 at 10:31 PM"
f.date(from: s2)! //"Jan 1, 2000 at 2:31 PM"
f.date(from: s1)! > f.date(from: s2)! // true
There's no standard type for a time-of-day. A reasonable type to start with is just a tuple:
typealias TimeOfDay = (hour: Int, minute: Int, second: Int)
To create these TimeOfDay values, you'll need a Calendar. By default, a Calendar uses the device's system-wide time zone. If you don't want that, set the Calendar's time zone explicitly. Example:
var calendar = Calendar.autoupdatingCurrent
calendar.timeZone = TimeZone(abbreviation: "UTC")!
Now you can use a DateFormatter to convert strings to Dates (if necessary), and then use calendar to extract the time-of-day components from the Dates:
let strings: [String] = ["2017-01-13 11:40:17 +0000", "2016-03-15 10:22:14 +0000"]
let parser = DateFormatter()
parser.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
let timesOfDay: [TimeOfDay] = strings.map({ (string) -> TimeOfDay in
let components = calendar.dateComponents([.hour, .minute, .second], from: parser.date(from: string)!)
return (hour: components.hour!, minute: components.minute!, second: components.second!)
})
Swift.print(timesOfDay)
// Output: [(11, 40, 17), (10, 22, 14)]
Finally, you can compare these TimeOfDay values. Swift comes with standard comparison operators for tuples whose elements are Comparable, so this TimeOfDay type qualifies. You can just say this:
if timesOfDay[0] < timesOfDay[1] {
Swift.print("date[0] comes first")
} else if timesOfDay[0] == timesOfDay[1] {
Swift.print("times are equal")
} else {
Swift.print("date[1] comes first")
}
Let say we got two dates in string format:
// "2017-01-13 11:40:17 +0000"
// "2016-03-15 10:22:14 +0000"
We need to convert this strings to Date format, we create DateFormatter() and set the format ("yyyy-MM-dd' 'HH:mm:ssZ") it gonna convert
//date formatter converts string to date in our case
let firstDateFormatter = DateFormatter()
firstDateFormatter.dateFormat = "yyyy-MM-dd' 'HH:mm:ssZ"
Now we can get our date from string to Date format
//convert string to dates
if let date1 = firstDateFormatter.date(from: "2017-01-13 09:40:17 +0000"),
let date2 = firstDateFormatter.date(from: "2016-03-15 10:22:14 +0000") {
What we want is to compare only Hours and Minutes. So change dateformat to "HH:mm"
//we ve got the dates, now switch dateformat for other job
firstDateFormatter.dateFormat = "HH:mm"
Now get the string value from our date, that only contain "HH:mm"
// convert date to string ( part of string we want to compare )
let HHmmDate1 = firstDateFormatter.string(from: date1) //"17:40"
let HHmmDate2 = firstDateFormatter.string(from: date2) //"18:22"
Final step is to get date from our "HH:mm" values, let say we ask DateFormatter to give us a date, based on time only, in our case "17:40" and "18:22". DateFormatter will put some values for dates, so we get Jan 1, 2000 automatically for both dates, but it will get the time we provide.
//produce "default" dates with desired HH:mm
//default means same date, but time is different
let HH1 = firstDateFormatter.date(from: HHmmDate1) //"Jan 1, 2000 at 5:40 PM"
let HH2 = firstDateFormatter.date(from: HHmmDate2) //"Jan 1, 2000 at 6:22 PM"
Now we could easily compare dates
//compare
HH1! > HH2!
}
There are many options to compare dates with Calendar also
This is very simple in Swift if you use Swifter Swift
date1.day = 1
date1.month = 1
date1.year = 2000
date2.day = 1
date2.month = 1
date2.year = 2000
now you can use >,<,== operators on date1 and date2 to compare just the time components.
edit - you could do this your self by extending the date class, for example swifter-swift does the bellow for the day component.
public var day: Int {
get {
return Calendar.current.component(.day, from: self)
}
set {
let allowedRange = Calendar.current.range(of: .day, in: .month, for: self)!
guard allowedRange.contains(newValue) else { return }
let currentDay = Calendar.current.component(.day, from: self)
let daysToAdd = newValue - currentDay
if let date = Calendar.current.date(byAdding: .day, value: daysToAdd, to: self) {
self = date
}
}
}