I need to construct NSDate object from String, so I wrote the following code:
func getNSDateObjectFromString(string: String) -> NSDate {
var formatter = NSDateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
let date = formatter.dateFromString(string)
return date!
}
Unfortunately, the input string sometimes may contain milliseconds too. What can I do in this case? I don't find any way to read milliseconds (not in the day) according to the http://www.unicode.org/reports/tr35/tr35-31/tr35-dates.html#Date_Format_Patterns
Thanks in advance.
As far as I know, the format doesn't support "optional" fields. So you have to try the formats one by one:
func getNSDateObjectFromString(string: String) -> NSDate {
var formatter = NSDateFormatter()
formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX")
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
var date = formatter.dateFromString(string)
if date == nil {
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.S"
date = formatter.dateFromString(string)
}
return date!
}
You can try something like:
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS"
A Swift 3 Solution
After a bit of trial and error with the date format this is what worked for me with Swift 3.
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss.SSS"
let date = formatter.date(from: "2017-03-11 13:16:31.177")!
debugPrint(dateFormatter.string(from: date))
and after a round trip results in the expected debug output of
"2017-03-11 13:16:31.177"
Note that using the format "yyyy-MM-dd'T'HH:mm:ss.SSS" resulted in formatter.date(from: returning a nil optional Date.
Are they important?
In DateFormatter you create your matching string in years, months, days, hours, mins, secs, but you don't need to. If your matching string does not contain any of them, formatter will just ignore them.
Related
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
I receive dates as String like this one:
"2016-05-20T12:25:00.0"
I want to get its corresponding NSDate object, and I'm trying this way:
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "YYYY-MM-DDThh:mm:ss.s"
let date = dateFormatter.dateFromString(dateStr)
where dateStr is like the example I wrote first. I took the dateFormat string from this page, but I get a nil date, what is wrong there?
Thanks in advance
You have a few problems with your date format. First Y is for weekOfYear, D is for day of year. hh is used for 12 hours format, decimal second you should use capital S and you need to escape the 'T'
You should do as follow:
let dateString = "2016-05-20T12:25:00.0"
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.S"
if let date = dateFormatter.dateFromString(dateString) {
print(dateFormatter.stringFromDate(date) ) // "2016-05-20T12:25:00.0\n"
}
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.S"
if let date = dateFormatter.stringFromDate(NSDate()) {
print(dateFormatter.stringFromDate(date) )
}
I've got a date stored in my database and I want to retrieve it and display it nicely in my tableview cells.
The format it comes in from the database and stored in option1 is BO05151530
Where the first two letters have meaning in the program but are not needed for the date so I take those off using the substringFromIndex function.
So what is left is 05151530 where it represents MMddhmm
I would like to display it nicely like MM-dd # h:mm a
For example 12-05 # 3:45 am
Here is what I tried but unfortunately ns_date1 comes up as nil each time.
What would you suggest I do?
let date1 = option1.substringFromIndex(option1.startIndex.advancedBy(2))
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "MMddhhmm"
let ns_date1 = dateFormatter.dateFromString(date1)
Try this. you don't need to separate BO NSDateFormatter can handle extra string
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "'BO'MMddHHmm"
let ns_date1 = dateFormatter.dateFromString("BO05151530")
dateFormatter.dateFormat = "'BO' MM-dd # hh':'mm a"
let string = dateFormatter.stringFromDate(ns_date1!)
try
dateFormatter.dateFormat = "MMddHHmm"
HH is 24 hour format and hh is 12 hour format. you need the 24 one
Check out this app, this will help you know the right format and give you code
https://itunes.apple.com/ae/app/date-format-creator/id965645209?mt=12
NOTE: you need to add year to get a correct NSDate
I have this function :
class func getTheDateString(stringForInputDate: String, fromFormat inputFormat: String, toFormat outputFormat: String) -> String {
let formatter: NSDateFormatter = NSDateFormatter()
formatter.dateFormat = inputFormat
formatter.timeZone = NSTimeZone.localTimeZone()
let dateForInput: NSDate = formatter.dateFromString(stringForInputDate)!
formatter.dateFormat = outputFormat
return formatter.stringFromDate(dateForInput)
}
and used it as:
let stringDate : String = "0515930" // "05151530"
if stringDate.lengthOfBytesUsingEncoding(NSUTF8StringEncoding) < 8 {
print([ViewControllerForScreen1 .getTheDateString(stringDate, fromFormat: "MMddHmm", toFormat: "MM-dd # h:mm a")]);
}else {
print([ViewControllerForScreen1 .getTheDateString(stringDate, fromFormat: "MMddHHmm", toFormat: "MM-dd # h:mm a")]);
}
OUTPUT:
["05-15 # 9:30 AM"]
["05-15 # 3:30 PM"]
I am trying to parse some json which is the result of an oData connection and I am getting the following response from the server:
"Task_ID":24,"Equipment_ID":3,"Owner_ID":2,"Priority":5,"Date_Due":
"2015-04-08T19:37:56.913","Time_Complete":"2015-04-09T19:37:56","Task_Description"
I am actually interested at the two different date fields I am receiving:
"Date_Due":"2015-04-08T19:37:56.913"
and
"Time_Complete":"2015-04-09T19:37:56"
As we can see, one has the millisecond timestamp and the other one does not.
By looking at the DB, this happens because the millisecond is actually .000 in the database (MS SQL Server) and for whatever reason, the result I receive in my json has this part truncated.
I am not interested in the milliseconds but I would like to have a dateFormat function that can handle both scenarios.
Now I have an obvious answer which is (pre)parse every date field, remove the milliseconds if they are there and then use the following code to format them:
let SQLDateFormatter: NSDateFormatter = {
let formatter = NSDateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX")
formatter.timeZone = NSTimeZone(forSecondsFromGMT: 0)
return formatter
}()
However I would like to know if we can build a formatter that can solve this issue without pre-parsing, something that would be able to take both:
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
and
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS"
and automatically do the formatting properly.
I have been checking for this issue but could not find anything out there, thanks in advance...
extension Formatter {
static let iso8601: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.timeZone = TimeZone(secondsFromGMT: 0)
return formatter
}()
static let iso8601withFractionalSeconds: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS"
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.timeZone = TimeZone(secondsFromGMT: 0)
return formatter
}()
}
extension String {
var date: Date? {
return Formatter.iso8601withFractionalSeconds.date(from: self) ??
Formatter.iso8601.date(from: self)
}
}
"2015-04-08T19:37:56.913".date // "Apr 8, 2015, 4:37 PM"
"2015-04-09T19:37:56".date // "Apr 9, 2015, 4:37 PM"
No, NSDateFormatter will return nil if the string is not in the exact dateFormat as specified.
What you can do instead of preprocessing the string, is just check if the string you got is with miliseconds or without.
The best way to do this is using Regex. The idea is to create the SQLDateFormatter like you normal, and then check if the string has miliseconds or not. If there are miliseconds included, just change the dateFormat - way better than parsing the string.
if let match = tes.rangeOfString("(\\d{4}-\\d\\d-\\d\\d[T](\\d\\d:){2}\\d\\d.\\d{3})", options: NSStringCompareOptions.RegularExpressionSearch)
{
SQLDateFormatter.format = "yyyy-MM-dd'T'HH:mm:ss.SSS"
}