When I am using NSDateformatter to get date from string it returns wrong value.I dont know what must be reason.Please help me to resolve.
Thanks in advance.
Input String:-
newDate "06:11"
end time "07:00"
start time "05:00"
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "HH:mm"
let date:NSDate = dateFormatter.dateFromString(dateString)!
println(date)
Output Date:-
current date 2000-01-01 00:41:00 +0000
end date 2000-01-01 01:30:00 +0000
start date 1999-12-31 23:30:00 +0000
By doing
println(date)
You are printing the description of the date, which is equal to -
println(date.description())
And it always prints the time in UTC (GMT)
So if you are in UTC+5:30, it will display time that is before 5:30 hours than your entered time. If you want to print date in your timezone, use a NSDateFormatter again. To see date of other time zone, set NSDateFormatter timeZone.
Hope this explains.
Related
Here is my DateFormatter Code
let formatter = DateFormatter()
formatter.dateFormat = "MMM dd"
let dateString = formatter.string(from: date)
Now:
po dateString
gives the result "May 18"
po date gives the result 2021-05-17 18:30:00 +0000
This does not make sense to me - why is the Date May 17 2021 being converted to the String May 18?
A Date object records an instant in time anywhere on the planet.
That instant in time will be on a different calendar day (day/month/year) depending on what time zone you are in.
By default, date formatters work in the device's current time zone.
When you log a Date using po date or print(date) the default description of a Date displays that date in UTC using the ISO 8601 date format. Depending on the user's time zone, the Date in UTC might be on a different calendar day than it is in the local time zone
If you want to log a date in the user's local time zone, use po date.description(with: Locale.current) or po DateFormatter.localizedString(from: date, dateStyle: .medium, timeStyle: .medium)
This depends on the current time zone of the formatter used , for 0 based use
formatter.timeZone = TimeZone(abbreviation: "UTC")
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 am struggling with Date and I'm assuming is TimeZone.
Currently I get from my backend a string like this "2020-04-07" and when I try to convert it to date it turns into 2020-04-06 22:00:00 +0000. I am in Spain (UTC+2) which I guess this is why it removes 2 hours?
This is my date formatter:
var dateFormatter: DateFormatter = {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
dateFormatter.timeZone = TimeZone.current
return dateFormatter
}()
And I call it dateFormatter.date(from: startDateString)
I am setting my current timezone but seems to be ignoring it or am I missing something?
I have followed a lot of answers from here but it's always the same result.
Thank you
The Date object does not have any inherent locale / time zone. It just represents a moment in time. If you want to see that Date as a string in a specific locale/time zone you have to use a date formatter. Or there's descriptionWithLocale. If you use print it will print a debug description of the Date instance in UTC.
I am trying to convert UTC Date to local date in swift but after get UTC To Local date in string i convert that string to again in NSDate but i am always getting in UTC date format, below is my code
Date : in UTC : 2016-07-20 18:30:00 +0000
I am trying this date in local date, check below code:
let dateInUTC = NSDate()
let seconds: Int = NSTimeZone.systemTimeZone().secondsFromGMT
print(seconds)
let localDateFormatter: NSDateFormatter = NSDateFormatter()
localDateFormatter.dateFormat = "MM/dd/yyyy HH:mm"
localDateFormatter.timeZone = NSTimeZone(forSecondsFromGMT: seconds)
let lastDate: String = localDateFormatter.stringFromDate(dateInUTC)
print(lastDate)
at this time i am getting “07/12/2016 16:56:36 GMT+5:30”, means i got local date in string but i want this date in NSDate so again i convert this string date in NSDate,check below
let getDate:NSDate = localDateFormatter.dateFromString(lastDate)!
print(getDate)
but at this stage again i got date in UTC (2016-07-12 11:26:36 +0000) but i want in local date,
I tried a lot of times in Swift but not getting local date from string,this line of code i used in objective-c, its working fine in obj-c but when i am trying in swift i always get UTC date,suggest me and give me right way to sol this.
NSDates don't save time zone information. You always have to use the dateFormatter with time zone when retrieving.
I need to store Date variable in CoreData in iOS
I need to store the Date only without the Time, So I made a formatter that discard the time partition from the NSDate variable.
But I have a strange result:
This is my code:
let dateStr = "2016-02-14 11:27:01"
let df2 = NSDateFormatter()
df2.timeZone = NSTimeZone.defaultTimeZone()
df2.dateFormat = "yyyy-MM-dd HH:mm:ss"
print(dateStr)
if let date = df2.dateFromString(dateStr) {
df2.dateFormat = "yyyy-MM-dd"
print("-> \(df2.dateFromString(df2.stringFromDate(date)))")
}
and this is the output:
2016-02-14 11:27:01
-> Optional(2016-02-13 20:00:00 +0000)
Why does the formatter decrease the day by one ?
I tried many dates with same issue
Your time zone is obviously UTC+4.
To get UTC set the time zone accordingly.
df2.timeZone = NSTimeZone(forSecondsFromGMT: 0)
But although you see a date 4 hours ago the NSDate object is treated correctly depending on your time zone. The print command displays always UTC ignoring the time zone information, because NSDate is just a wrapper for a Double number.