I have a date string coming from back-end as "2022-08-16T13:44:11.8743234". Date formatting and conversion is the oldest skill in the book but I cannot figure out why I'm unable to convert that string to a Date object in Swift iOS. I just get nil with any source format I specify.
private func StringToDate(dateString: String) -> Date?
{
let formatter = DateFormatter()
formatter.dateFormat = "YYYY-MM-DDTHH:mm:ss.[nnnnnnn]"
let date = formatter.date(from: dateString)
return date //this is nil every time
}
DateTime2 is a more precise SQL Server extension of the normal C# DateTime, hence why the date string has 7 decimal places afters the seconds.
What am I doing wrong?
In your code the way you are handling the millisecond part is wrong. We use usually .SSS for milliseconds. Take a look at here it shows all the symbols related to date format.
let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS"
let date = dateFormatter.date(from: "2022-08-16T13:44:11.8743234")
print(date)
In addition to that you are using DD for day. DD means the day of the year(numeric). So it should be dd. Same case is applied for the year as well.
Related
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.
This question is not asked for the first time, but no solution works for me. I am getting time in String from Api response in the following format "14:45".
I want to compare this time with the current time, for this purpose I need to convert this string in Time formate(swift sports)
I always get nil after conversion
I have tried multiple ways but none of them worked for me and one is given for reference, I don't know what am I missing here
Thanks for any response
func stringToTime(str:String) -> Date{ // 14:45 passed here in str
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "hh:mm a"
print(str)
//here time string prints
let date = dateFormatter.date(from: (str))
print(date)
//date is nil here, should be 02:45 pm
return date!
}
If the time you get from the API is in 24h format you can do a string comparison
let formatter = DateFormatter()
formatter.dateFormat = "HH:mm"
let currentTime = formatter.string(from: Date())
let compare = currentTime.compare("14:45")
You might need to set the time zone for the DateFormatter to make sure it uses the same as the API
It seems like you want to transform a time string in one format to another format. Your method signature should look like this:
func changeFormat(str:String) -> String {
Note that you should not output a Date here, because Dates don't have formats. They will always be printed in the same way. What you need to do in this method is 2 things:
parse str to a Date using a DateFormatter, specifying the format HH:mm. You seem to assume that DateFormatter can automatically work this format out. It can't :(
format the Date object you just got using a DateFormatter, specifying the format hh:mm a. This produces a string, not a date.
(You could also consider having the method return a Date (then it would be called parseTime), and do the second step just before you show the date to the screen.)
func changeFormat(str:String) -> String {
let dateFormatter = DateFormatter()
// step 1
dateFormatter.dateFormat = "HH:mm" // input format
let date = dateFormatter.date(from: str)!
// step 2
dateFormatter.dateFormat = "hh:mm a" // output format
let string = dateFormatter.string(from: date)
return string
}
Hello I need to change the date format
I getting a response from backend like
dob = "1989-03-06T00:00:00Z";
in my case, I write the following code but my app is crashed i think my current date format is wrong.
func DateFromWebtoApp(_ date: String) -> String {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
let date = dateFormatter.date(from: date)
dateFormatter.dateFormat = "MM-dd-yyyy"
return dateFormatter.string(from: date!)
}
Please look at the date string. There are no milliseconds (S) and the Z is a format specifier (no single quotes).
Further for an arbitrary date format add always a fixed Locale
func dateFromWebtoApp(_ dateString: String) -> String {
let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
let date = dateFormatter.date(from: dateString)
dateFormatter.dateFormat = "MM-dd-yyyy"
return dateFormatter.string(from: date!)
}
Try this, Its work on my side.
func DateFromWebtoApp(_ date: String) -> String
{
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
let date = dateFormatter.date(from: date)
dateFormatter.dateFormat = "MM-dd-yyyy"
dateFormatter.timeZone = .current
return dateFormatter.string(from: date!)
}
Since that input date string is in a ISO complaint date format you can use ISO8601DateFormatter.
func dateFromWebtoApp(_ inDate: String) -> String? {
let inFormatter = ISO8601DateFormatter()
if let date = inFormatter.date(from: inDate) {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MM-dd-yyyy"
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
return dateFormatter.string(from: date)
}
return nil
}
Since constructing date formatters is somewhat expensive it might be worthwhile to declare them outside of the function and keep them around if possible
Date formatters are notoriously computationally intensive to create. They’re also computationally expensive to change the dateFormat. So I’d suggest you declare two date formatter properties up front, and instantiate them once and only once.
let isoDateFormatter = ISO8601DateFormatter()
let dobFormatter: DateFormatter = {
let formatter = DateFormatter()
formatter.dateStyle = .medium
formatter.timeZone = TimeZone(secondsFromGMT: 0)
return formatter
}()
The first, isoDateFormatter is for converting strings from your backend into Date objects. By using ISO8601DateFormatter, it gets you out of the business of manually configuring the locale for a DateFormatter.
The second, dobFormatter is for converting the date of birth Date object into a string to be presented in your UI. For this second formatter, please note that:
I don’t use dateFormat, but rather dateStyle (so the result honors the particular device’s date localization preferences, where UK users will see “6 Mar 1989”, but US users will see “Mar 6, 2019”). Use .short rather than .medium if you really want to see dd/MM/yy for UK users and MM/dd/yy for US users. But I personally like the medium format, as it is both reasonably concise but also completely unambiguous. Of, if I have space, I use the long format, which represents date most naturally (e.g. “March 6, 2019” rather than “Mar 6, 2019”). Do whatever your UI demands.
But if this is for presentation to the end user, you really should avoid hard-coded date format strings as users want to see dates presented in a manner consistent with their personal device-wide localization settings, not what one app or the other prefers. And there’s no reason to limit your app to US users, because some day you might want to reach a broader audience.
I set the time zone for this output formatter to be GMT because this string represents a date, not a combined date/time. E.g., 1989-03-06T00:00:00Z, which is midnight on March 6, 1989 GMT, translates to is 4pm on March 5th for us in California. But when you present the birthdate, you want to say March 6th, not March 5th. In short, you want to ignore the time and timezone information. You do this by using GMT/UTC/Zulu for your output date formatter.
Anyway, you’d then use it like so:
let input = "1989-03-06T00:00:00Z"
if let dob = isoDateFormatter.date(from: input) {
let output = dobFormatter.string(from: dob)
}
i am passing "01/12/2017" in the fromDate.text(textfield), but receiving unexpected output.
let formatter = DateFormatter.init()
formatter.dateFormat = "dd/mm/yyyy"
startDate = formatter.date(from: fromDate.text!)
print("startDate = \(startDate)")
output is : 31/12/2016
The format of date should be dd/MM/yyyy not dd/mm/yyyy. The mm indicates the minutes and MM indicates the month.
And also add the below line in your code
formatter.timeZone = TimeZone(abbreviation: "GMT+0:00")
This line of code set time zone. If you not, then you get 30/11/2017 in output.
The reason behind this is when string date not contain time then formatter assume that it is midnight and you also not given the timezone so it will take current timezone.
It has to be dd/MM/yyyy dateformat. MM in capital.
func convertToString(of dateTo: Date) -> String {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd/MM/yyyy" //Your New Date format as per requirement change it own
let newDate: String = dateFormatter.string(from: dateTo) //pass Date here
print(newDate) //New formatted Date string
return newDate
}
I've watching trough stack overflow to find the answer and I can't find it I want to cast this string value "1900-01-01T00:00:00" to Date format, I was trying with some formats like those:
"yyyy-MM-dd HH:mm:ss"
"EEE, dd MMM yyyy hh:mm:ss +zzzz"
"YYYY-MM-dd HH:mm:ss.A"
"yyyy-MM-dd HH:mm:ss.S"
but anyone of those its working.
and I want the date format like this
"dd-mm-yyyy"
Hope you can help me!
Thanks.
It is a two step process, first converting 1900-01-01T00:00:00 (known as a RFC 3999 or ISO 8601 date, referred to the specifications that define this format) into a Date object, and then converting that Date object back to a string in the form of 01-01-1900:
To convert your string in the form of 1900-01-01T00:00:00 into a Date object, you can use ISO8601DateFormatter:
let formatter = ISO8601DateFormatter()
formatter.formatOptions.remove(.withTimeZone)
let date = formatter.date(from: string)!
That is equivalent to the following DateFormat, in which one has to manually set the locale to en_US_POSIX (because RFC 3999/ISO 8601 dates use a Gregorian calendar, regardless of what the device's default calendar type) and sets the timeZone to GMT/Zulu, because usually RFC 3999/ISO 8601 dates are representing GMT unless specified otherwise:
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.timeZone = TimeZone(secondsFromGMT: 0)
let date = formatter.date(from: string)!
For more information about the importance of timezones and locales in parsing RFC 3999 and ISO 8601 dates, see Apple's Technical Q&A 1480.
Then, to convert that Date object to a string into 01-01-1900 (day, month, and year), you'd use a format string of dd-MM-yyyy (note the uppercase MM for "month", to distinguish it from mm for "minute"):
let formatter2 = DateFormatter()
formatter2.dateFormat = "dd-MM-yyyy"
let string = formatter2.string(from: date)
Two observations regarding the dateFormat string:
If this string is for displaying to the user, you might use use dateStyle rather than dateFormat, e.g.:
formatter2.dateStyle = .short
While this will generate a slightly different format, e.g. dd/MM/yy, the virtue of this approach is that the string will be localized (e.g. UK users will see MM/dd/yyyy, their preferred way of seeing short dates).
It just depends upon the purpose of your dd-MM-yyyy format. If it's for internal purposes, go ahead and use dateFormat. But if it's for showing dates in your UI, use dateStyle instead, and enjoy the localization that DateFormatter does automatically for you. For more information, see "Working With User-Visible Representations of Dates and Times" section of the DateFormatter reference.
Note that in the absence of a timeZone specified for this second formatter, it assumes that while the ISO 8601 date was in GMT, that you want to see the date in your local timezone. For example, (1900-01-01T00:00:00 GMT was Dec 31, 1899 at 4pm in California). If you want to see the date string of the original ISO 8601 object, not corrected for timezones, you'd just set the timeZone of this second formatter to be GMT as well, e.g.
formatter2.timeZone = TimeZone(secondsFromGMT: 0)
As others have pointed out, you want to avoid unnecessarily re-instantiating DateFormatter objects. So you might put these formatters in properties that are instantiated only once, or use an extension:
extension DateFormatter {
static let customInputFormatter: ISO8601DateFormatter = {
let formatter = ISO8601DateFormatter()
formatter.formatOptions.remove(.withTimeZone)
return formatter
}()
static let customOutputFormatter: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "dd-MM-yyyy"
formatter.timeZone = TimeZone(secondsFromGMT: 0) // if you want date in your local timezone, remove this line
return formatter
}()
}
And then:
let input = "1900-01-01T00:00:00"
let date = DateFormatter.customInputFormatter.date(from: input)!
let output = DateFormatter.customOutputFormatter.string(from: date)
print(output)
This is how I do custom date formatters:
extension DateFormatter {
static let inDateFormatter: DateFormatter = {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
return dateFormatter
}()
static let outDateFormatter: DateFormatter = {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd-mm-yyyy"
return dateFormatter
}()
}
And then use it like:
if let date = DateFormatter.inDateFormatter.date(from: "1900-01-01T00:00:00") {
let newDateString = DateFormatter.outDateFormatter.string(from: date);
print(newDateString) //prints 01-00-1900
}
This avoids any potential performance issues and is clear at the point of use, while still being concise.
Use this extension I created, where you can pass the format as a parameter.
extension String
{
func toDate( dateFormat format : String) -> Date
{
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = format
if let date = dateFormatter.date(from: self)
{
return date
}
print("Invalid arguments ! Returning Current Date . ")
return Date()
}
}
"1900-01-01T00:00:00".toDate(dateFormat: "yyyy-MM-dd'T'HH:mm:ss") //Plyground call test