I want to convert a string that was generated by the user to a Date data type. I want the time to be in 24-hour format
let dateFormatter = DateFormatter()
let timeAsString : String = "22:30"
dateFormatter.dateFormat = "HH:mm"
let timeFromString = dateFormatter.date(from: timeAsString)
result : "Jan 1, 2000 at 10:30 PM"
but the result is in 12-hour format. How can I get 22:30 as a Date data type?
Date has no format, so only can change the string converted from the date
Swift 4
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm"
let newDateString = dateFormatter.string(from: yourDate)
for different date format, you can check nsdateformatter.com
You code is absolutely correct, there no problem in your code. String HH in date format represent 24 hours time display format.
But developer (application) has no control over time format. You can set date format string supporting 24 hours time but if user has (not enabled) turned of 24 hours support from device then it will display time for 12 hours format.
Check your simulator/mac system/iPhone device time format and set it for 24 hours display.
Refer this apple document for 24 hours time support: Date Formatters
The representation of the time may be 13:00. In iOS, however, if the user has switched 24-Hour Time to Off, the time may be 1:00 pm.
func convertToString(of dateTo: Date) -> String {
let dateFormatter = CustomDateFormatter()
//Your New Date format as per requirement change it own
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
let newDate: String = dateFormatter.string(from: dateTo) //pass Date here
// print(newDate) //New formatted Date string
return newDate
}
Related
I'm using FSCalendar in a Swift app, and when user selects a day, I'm printing the selected day, and the it prints the previous day, at 23:00. I'm not sure why and how can I solve this. I'm in spain. Maybe it's related with where you are and your local hour?
This is how I'm printing the selected day:
extension CalendarDataViewViewController: FSCalendarDataSource {
func calendar(_ calendar: FSCalendar, didSelect date: Date, at monthPosition: FSCalendarMonthPosition) {
let df = DateFormatter()
df.dateFormat = "yyyy-MM-dd hh:mm:ss"
let now = df.string(from: date)
logger.debug("Date: \(date)")
}
}
And this is what it's printed when I select 18 march:
21:01:24.646 💚 DEBUG CalendarDataViewViewController.calendar():258 - Date: 2021-03-17 23:00:00 +0000
Your code creates a date formatter, converts the returned date to a date string with that formatter, and then ignores that and simply prints the date, which is being displayed in UTC. (Note the output Date: 2021-03-17 23:00:00 +0000)
Change your log command to read:
logger.debug("Date: \(now)")
And by the way, the variable name now is a terrible choice for holding a user-selected date that is not the current date.
I'd suggest renaming the returned date parameter selectedDate and the String output of the formatter as selectedDateString
Edit:
Consider this code:
import Foundation
func dateStringFromDate(_ inputDate: Date) -> String {
let df = DateFormatter()
df.dateFormat = "yyyy-MM-dd hh:mm:ss a"
let dateString = df.string(from: inputDate)
return dateString
}
func isoDateStringFromDate(_ inputDate: Date) -> String {
let df = ISO8601DateFormatter()
df.formatOptions = .withInternetDateTime
df.timeZone = TimeZone.current //Force the formatter to express the time in the current time zone, including offset
let dateString = df.string(from: inputDate)
return dateString
}
let now = Date()
print("Current timezone = \(TimeZone.current)")
print("now in 'raw' format = \(now)")
let localizedDateString = DateFormatter.localizedString(from: now,
dateStyle: .medium,
timeStyle: .medium)
print("localizedString for the current date = \(localizedDateString)")
print("dateStringFromDate = \(dateStringFromDate(now))")
print("isoDateStringFromDate = \(isoDateStringFromDate(now))")
Right now, at about 9:16 PM EDT on Thursday March 18th, that logs the following:
Current timezone = America/New_York (current)
now in 'raw' format = 2021-03-19 01:16:52 +0000
localizedString for the current date = Mar 18, 2021 at 9:16:52 PM
dateStringFromDate = 2021-03-18 09:16:52 PM
isoDateStringFromDate = 2021-03-18T21:16:52-04:00
The 'raw' date format is in GMT, with an offset value of 0. In that form, in GMT, the calendar date is already March 19th. (Because GMT is 4 hours ahead of EDT)
The class function NSDateFormatter.localizedString(from:dateStyle:timeStyle) displays a date in the current time zone and using the device's locale settings. The dateStyle and timeStyle parameters give you the option to choose whether or not, and in what format (short, medium, or long) to display the date or time.
An ISO8601DateFormatter displays the date following the conventions in the ISO8601 standard. The isoDateStringFromDate(:) function above uses the .withInternetDateTime option to express the date in the ISO8601 "internet date and time" format. I forced that date to be in the local time zone, so it displays the date with a -4 hour offset from GMT (since it is EDT, eastern daylight savings time where I live.)
The function dateStringFromDate(_:) is a slight variation on your function. It returns a date string in the current time zone, using 12 hour times and an AM/PM string.
I need to convert my date to string and then string to date. date is "2020-10-17 1:22:01 PM +0000"
Here is my date to string conversion code:
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssXXXXX"
let string = formatter.string(from: "2020-10-17 1:22:01 PM +0000")
let createdAT = string
its returning "2020-10-17 18:51:30+05:30"
Here is my string to date conversion code:
let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd' 'HH:mm:ssZ"
let date = dateFormatter.date(from:date)!
its returning "2020-10-17 1:21:30 PM +0000 - timeIntervalSinceReferenceDate : 624633690.0"
its returning the wrong date after i convert string to date. i need "2020-10-17 18:51:30+05:30" this time to be return when i convert string to date.....
The code in your question is muddled up. You try to convert a string into a string in the first example and something unspecified into a Date in the second example.
Here's how to convert a Date into a String:
import Foundation
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssXXXXX"
let string: String = formatter.string(from: Date())
print(string) // prints for example 2020-10-18T10:54:07+01:00
Here's how to convert a string into a date
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = "yyyy-MM-dd' 'HH:mm:ssZ"
let date: Date = formatter.date(from: "2020-10-18 10:59:56+0100")! // In real life, handle the optional properly
print(date) // prints 2020-10-18 09:59:56 +0000
When you print a Date directly, it automatically uses UTC as the time zone. This is why it changed it in the code above.
In the examples, I explicitly specified the type of string and date to show what type they are. Type inference means you can omit these in normal code.
As a general rule when handling dates:
always use Date in your code. Date is a type that stores the number of seconds since Jan 1st 1970 UTC.
Only convert dates to strings when displaying them to the user or communicating with an external system.
When calculating periods etc, always use a Calendar to get things like date components and intervals in units other than seconds. You might think to get "the same time tomorrow" you could just add 24 * 60 * 60 to a Date but in many countries, like mine, that will work on only 363 days in the year. Calendar will correctly handle things like daylight saving and leap years.
hi I want to get current hour and minute from Date(), so I need to format it into string and want to bring back into date again. But after I try to convert to date the year change into 2000, how can I got back to current year.
//date formatter
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm"
dateFormatter.timeZone = TimeZone.current
// Get current time and format it to compare
var currentTime = Date() //Get current time
let currentTimeStr = dateFormatter.string(from: currentTime) //get current time only hour and minute
currentTime = dateFormatter.date(from: currentTimeStr)! //this is where the problem because the year change into 1 January 2000
From what I read in the comments, I think you want both the current time in a Date object and also a string with only hours and minutes in "HH:MM" format.
The problem comes from trying to use a formatter that doesn't have a year specified. You are overwriting the currentTime from a string that doesn't have a year (or day, or month) defined, so it defaults to Jan 1st 2000 (the hours and minutes should be correct).
You're also saying you need to format it into a String, and then go back to a Date object. You don't, you already have all the data you need in the Date object, so keep it around and use it when you need to. If this means creating a bunch of DateFormatters all over your project, you can always extend Date to have a function or variable that returns the string with the format you want.
extension Date {
var hoursAndMinutesString: String {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm"
dateFormatter.timeZone = TimeZone.current
return dateFormatter.string(from: self)
}
}
Then just call the function from the Date object when you need to, like this:
currentTime.hoursAndMinutesString
I have the following string:
let dateString = "2018-04-18T04:54:00-04:00"
I initialize a Date via the ISO8601DateForamtter by doing the following:
let formatter = ISO8601DateFormatter()
let date = formatter.date(from: dateString)
If I print the date, I get the following:
Apr 18, 2018 at 1:54am
The formatter is automatically converting the time into my local time. How can I prevent accounting for my time zone? For example, I want the Date object to show the following instead:
Apr 18, 2018 at 4:54am
With ISO8601, 2018-04-18T04:54:00-04:00 means 2018-04-18 04:54:00 in GMT -4h. To print the time as it is in the original string, you need to create a date formatter with the specific time zone which is -4.
let dateFormatter = DateFormatter()
dateFormatter.timeZone = TimeZone(secondsFromGMT: -4 * 60 * 60)
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
print(dateFormatter.string(from: date))
You will get
2018-04-17 04:54:00
FYI, I'm adding a link for ISO8601
You need to parse the timezone from your date string and use it to set the timezone from your date formatter:
func secondsFromGMT(from string: String) -> Int {
guard !string.hasSuffix("Z") else { return 0 }
let timeZone = string.suffix(6)
let comps = timeZone.components(separatedBy: ":")
guard let hours = comps.first,
let minutes = comps.last,
let hr = Int(hours),
let min = Int(minutes) else { return 0 }
return hr * 3600 + min * 60
}
let dateString = "2018-04-18T04:54:00-04:00"
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssxxxxx"
formatter.locale = Locale(identifier: "en_US_POSIX")
if let dateFromString = formatter.date(from: dateString) {
formatter.timeZone = TimeZone(secondsFromGMT: secondsFromGMT(from: dateString))
formatter.dateFormat = "MMM dd, yyyy 'at' h:mma"
formatter.amSymbol = "am"
formatter.pmSymbol = "pm"
print(formatter.string(from: dateFromString)) // Apr 18, 2018 at 4:54am
}
Instead of logging the Date directly, have a look at the string(from:timeZone:formatOptions:) method on ISO8601DateFormatter. With this, you should be able to get a date string for any time zone you desire.
You should set your formatter to the appropriate timezone such as (UTC example below):
formatter.timeZone = TimeZone(identifier: "UTC")
or alternatively specify against GMT:
formatter.timeZone = TimeZone(secondsFromGMT: 0)
The date that you are receiving from your current formatter is technically correct. Setting the date backwards as described in the currently accepted answer is not advised because you are effectively hard-coding an intended time zone. As soon as your device enters another time zone (or if a user downloads your app outside of the current time zone), your information will be incorrect.
If you are trying to display this time in the UTC time zone, you need to use another formatter to correctly format the output in the target time zone.
let utcFormatter = DateFormatter()
utcFormatter.timeZone = TimeZone(secondsFromGMT: 0)
// Perform any other transformations you'd like
let output = utcFormatter.string(from: date)
But why is your original date correct?
The Date API is incredibly robust and doing a lot of things under-the-hood, but is effectively implemented using a simple Double. The automaic time-zone information that it's displaying to you is an abstraction to make it easier to reason about. A date technically has no knowledge of what time zone it's in – but converting it to a string implicitly applies an inferred date formatter on the date and returns information it thinks will be most useful to you.
If you're doing manipulations on a date, you're likely using the Calendar API. You typically get a new instance from using Calendar.current, which will create a new calendar with your current time zone information. You can change the represented time zone of the calendar like this:
var calendar = Calendar.current
calendar.timeZone = TimeZone(secondsFromGMT: 0)
This will give you relative dates that will work in any time zone without modifying the base Date object that you're working with.
I have a date from a UIControl. I get date as string such as 06-12-2016 01:25 PM. Now I want to convert it into a format as 2016-12-06 13:25:00 I have tried below code t do so but it just gives me wrong date for ex. 2016-12-06 18:55:00. I have used below code for this:
func converStingToDate(str_date:String)->String
{
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy H:mm a"
let date = dateFormatter.date(from: str_date)
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
return dateFormatter.string(from: date!)
}
Please suggest me a better code. Also if you guys can help me to understand all this date formatting concept how it is done ?
The code is correct and the date is correct (although you should use h for 12-hour hour).
Your time zone is UTC+0530 and print() displays the date in UTC.
If you need to print the correct local time set the time zone of the formatter to UTC:
dateFormatter.timeZone = TimeZone(abbreviation: "UTC")`