In my app I need some kind of timer like countdown. Like for Next match there is 1 year 2 month 6 days 23 minutes 24 seconds and 5 milliseconds remaining.
For this I am using this code:
extension DateComponentsFormatter {
func difference(from fromDate: Date, to toDate: Date) -> String? {
self.allowedUnits = [.year,.month,.day,.hour, .minute, .second ,.nanosecond]
self.maximumUnitCount = 8
self.unitsStyle = .full
return self.string(from: fromDate, to: toDate)
}
}
But I am not getting milliseconds.
Here is what I am getting:
["24 years", " 8 months", " 20 days", " 12 hours", " 2 minutes", " 48 seconds"]
I need milliseconds.
You can't use a DateComponentsFormatter to format milliseconds. According to the documentation, only these calendar units are allowed:
year
month
weekOfMonth
day
hour
minute
second
You will have to format this yourself, by getting the TimeInterval between the dates, get the fractional part of the time interval, and format that.
Here is an idea of what this would look like.
extension DateComponentsFormatter {
func difference(from fromDate: Date, to toDate: Date) -> String? {
self.allowedUnits = [NSCalendar.Unit.second]
allowsFractionalUnits = true
self.maximumUnitCount = 8
self.unitsStyle = .full
guard let firstPart = self.string(from: fromDate, to: toDate) else { return nil }
let milliseconds = abs(toDate.timeIntervalSince(fromDate)).remainder(dividingBy: 1) * 1000
let numberFormatter = NumberFormatter()
numberFormatter.maximumFractionDigits = 0
guard let secondPart = numberFormatter.string(from: milliseconds as NSNumber) else { return nil }
return "\(firstPart) \(secondPart) milliseconds"
}
}
let formatter = DateComponentsFormatter()
formatter.difference(from: Date(), to: Date().addingTimeInterval(0.5))
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 would like to create not Date but simple quantities of time (i.e. durations) whose units are either days, weeks or months, then format them nicely as "1 day", "7 days", "3 weeks", "1 month", etc.
However both Duration and Measurement<UnitDuration> initializers do not accept these units.
// Type 'Duration' has no member 'days'
let duration: Duration = .days(7)
// Type 'UnitDuration' has no member 'days'
let measurement: Measurement<UnitDuration> = .init(value: 7, unit: .days)
I tried to extend UnitDuration but it does not allow to automatically format units to plural.
extension UnitDuration {
static let days = UnitDuration(
symbol: "days",
converter: UnitConverterLinear(coefficient: 60 * 60 * 24)
)
}
let measurement: Measurement<UnitDuration> = .init(value: 1, unit: .days)
measurement.formatted(.measurement(width: .wide, usage: .asProvided)) // "1 days" :(
The aim is to get something like this :
let onDay: Duration = .days(1)
let eightWeeks: Duration = .weeks(8)
oneDay.formatted() // "1 day"
eightWeeks.formatted() // "8 weeks"
As Fabio says, you could use a DateComponentsFormatter:
formatter = DateComponentsFormatter()
formatter.unitsStyle = .full
formatter.allowedUnits = [.weekOfMonth]
let components = DateComponents(weekOfMonth: 13)
if let string = formatter.string(from: components) {
print(string)
} else {
print("Unable to convert components to a String")
}
That code outputs "13 weeks" as expected.
Edit:
You can also request multiple different units, e.g. weeks, days, hours, and minutes, and the DateComponentsFormatter will compose a description of the time interval using multiple units. Example:
let formatter = DateComponentsFormatter()
formatter.unitsStyle = .full
formatter.allowedUnits = [.second, .hour, .day, .weekOfMonth]
let components = DateComponents(day: 2, hour: 3, weekOfMonth: 54 )
if let string = formatter.string(from: components) {
print(string)
} else {
print("Unable to convert components to a String")
}
That outputs "54 weeks, 2 days, 3 hours".
DateComponentsFormatter also has a func string(from: TimeInterval) function that will take an arbitrary number of seconds and express it in terms of the units you ask for.
This sounds like a scenario for an enum with associated values.
enum MyDuration{
case day(Int), week(Int), month(Int)
var formatted: String{
switch self{
case .day(let day):
return day == 1 ? "\(day) day" : "\(day) days"
case .week(let week):
return week == 1 ? "\(week) week" : "\(week) weeks"
case .month(let month):
return month == 1 ? "\(month) month" : "\(month) months"
}
}
}
let myDay: MyDuration = .day(3)
let myWeek: MyDuration = .week(1)
print(myDay.formatted)
print(myWeek.formatted)
Output:
3 days
1 week
I am not good at Swift so I would like to know how to calculate the current time is between two times.
I got the following response from the backend.
{"workHours":"M-F 9:00 - 18:00"}
From the above string, how to write a class/struct(or another best way) to validate today's current time is in the described time range("M-F 9:00 - 18:00")?
public final class DateValidator {
let startTime: Date?
let endTime: Date?
func isInRange() -> Bool {
// write modules here
// How to validate
}
public init(dateString: String) {
// dateString should be "M-F 9:00 - 18:00"
// Extract startTime and endTime from dateString
}
}
Set up the DateComponentsFormatter
let dcf = DateComponentsFormatter()
dcf.allowedUnits = [.day, .hour, .minute, .second]
dcf.unitsStyle = .full
Set up ordinary date formatter
let df = ISO8601DateFormatter()
df.formatOptions = [.withFullDate, .withDashSeparatorInDate]
Perform formatting
if let future = df.date(from: "2019-04-29"), let diff = dcf.string(from: Date(), to: future) {
print(diff)
}
Output is
3 days, 6 hours, 9 minutes, 9 seconds
I have 2 dates. I don't care about the date portion, just the time.
How can I compare 2 dates and get the timeinterval between 2 dates?
Should I set the dates to 01-01-2000 and leave the time alone to compare?
Use DateComponents and get the hour, minute, and second of the two dates. At this point you have to assume a full 24 hour, 86400 seconds per day. There's no need to worry about daylight saving or leap seconds or anything since you are doing date independent calculations.
Convert the hours, minutes, and seconds into total seconds of the day for the two dates. Then simply subtract the two totals and you have the difference.
Here's a helpful Date extension:
extension Date {
func secondsSinceMidnight() -> TimeInterval {
let comps = Calendar.current.dateComponents([.hour,.minute,.second], from: self)
return TimeInterval(comps.hour! * 3600 + comps.minute! * 60 + comps.second!)
}
func timeDifference(to date: Date) -> TimeInterval {
return date.secondsSinceMidnight() - self.secondsSinceMidnight()
}
}
Call timeDifference(to:) using your two dates and you will get the difference in seconds ignoring the date portion of the dates.
A negative result means that the to date is closer to midnight.
This is an alternative to rmaddy's solution completely based on DateComponents
extension Date {
func timeComponents() -> DateComponents {
return Calendar.current.dateComponents([.hour,.minute,.second], from: self)
}
func timeDifference(to date: Date) -> Int {
return Calendar.current.dateComponents([.second], from: date.timeComponents(), to: self.timeComponents()).second!
}
}
If you have two dates you can use the method timeIntervalSince(Date).
For instance:
func calculateElapsedTime(from someTime: Date) -> TimeInterval {
let currentTime = Date()
var elapsedTime = currentTime.timeIntervalSince(someTime)
return elapsedTime
}
If you only want to consider the time difference between the two dates, you first have to normalize the date. This can be done in the following cumbersome way:
let currentDate = Date()
let anotherDate = Date(timeInterval: 60, since: currentDate)
let formatter = DateFormatter()
formatter.timeStyle = .short
let currentTime = formatter.string(from: currentDate)
let anotherTime = formatter.string(from: anotherDate)
let currentIntervalTime = formatter.date(from: currentTime)
let anotherIntervalTime = formatter.date(from: anotherTime)
let elapsedTime = anotherIntervalTime?.timeIntervalSince(currentIntervalTime!)
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
}
}
}