Retrieve current date without leading zeroes - ios

I am trying to compare the date chosen on a calendar (Kal calendar implementation) with the current date. The issue is that the current date is in MM/dd/yyyy format, whereas the Kal dates will have no leading zeroes if the month or day is below 10. Is there an easy way to retrieve the current date so that it will not have leading zeroes for the day or month if it's under 10? (The current date will actually be utilized as an attribute for saved objects, so that they can later be queried using the date selected with Kal)
example current date - 07/07/2014
example Kal date - 7/7/2014

Don't compare strings holding dates. Create actual NSDate objects, using an NSDateFormatter, and compare those. The format strings you need are "MM/dd/yyyy" for your date, however you're retrieving it, and "M/d/yyyy" for Kal's date.

I have used en_US_POSIX along with "MM/dd/yyyy" & it's Working Fine
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = "MM/dd/yyyy"
https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/DataFormatting/Articles/dfDateFormatting10_4.html#//apple_ref/doc/uid/TP40002369-SW7

Related

How to know Date format getting from sever [duplicate]

This question already has answers here:
How can I parse / create a date time stamp formatted with fractional seconds UTC timezone (ISO 8601, RFC 3339) in Swift?
(13 answers)
Closed 1 year ago.
I am trying to get date format of a date that I am getting from server.
What will be the format of this date:
2021-10-14T17:53:03.753588+05:30
What I tried:
yyyy-MM-dd'T'HH:mm:ssXXX
But Its not working.
How to (my tips & steps):
When you are struggling to find the date format for String -> Date ask you this: What my format is really doing? What's it's parsing/interpreting? Just let's see with Date -> String...
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssXXX"
print(formatter.string(from: Date()))
Output: 2021-10-14T13:06:38+02:00: Is it the "same" as the string we have? No, some are the same, but not all...
Let's continue with another tip:
Let's put our format and the string one above the other one:
2021-10-14T17:53:03.753588+05:30
yyyy-MM-dd'T'HH:mm:ssXXX
Then, let's add "spaces", to make each pattern match its corresponding input:
2021-10-14 T 17:53:03.753588 +05:30
yyyy-MM-dd 'T' HH:mm:ss XXX
Then, let's check the doc (it's bookmarked in my web browser) for interpretation of the pattern and check if they correspond if needed, and to find the missing one if needed too.
Ok, so we aren't interpreting .753588 at all, that's why it's failing...
It's for the fractional seconds, so if we change the format to: "yyyy-MM-dd'T'HH:mm:ss.SSSXXX", it should work. Note, you can replace XXX with Z if you want...
Now, remember that patterns are case sensitive, so if you have strange hours, minutes, or nil because of that, check if you didn't misuse minutes vs month, 12h format vs 24 hour format...
If you have hours diff (or usually 30min diff), the issue could be then a timezone issue.
If you have a day diff, it could also be a timezone issue (interpret it as hours diffs around midnight, so there is a day change).
If you have a year diff, check if you didn't misuse yyyy vs YYYY.
Etc. But that should cover most of your cases (basic issues).
Try this format.
"yyyy-MM-dd'T'HH:mm:ss.SSSSSSXXX"
As the date format you mentioned in your question contains milliseconds as well as timezone offset info.
Once date is parsed then based on your need you can set output date format and will get formatted date.
let sampleDate = "2021-10-14T17:53:03.753588+05:30"
let dateFormatter = DateFormatter() dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSSSSXXX" // Set input date format.
let inputDate = dateFormatter.date(from: sampleDate)
print("Input Date:- \(inputDate)")
dateFormatter.dateFormat = "yyyy-MM-dd hh:mm:ss" // Set output date format as per need
let outputDate = dateFormatter.string(from: inputDate ?? Date())
print("Output Date:- \(outputDate)")

DateFormatter wrong time output when a different month is selected

I have a separate DatePicker and TimePicker component in my app.
Once the user has selected both the desired Date and Time, I construct a new Date object like this:
let timeStamp = Date(year: selectedDate.year, month: selectedDate.month, day: selectedDate.day, hour: selectedTime.hour, minute: selectedTime.minute)
I then use DateFormatter to output the exact time that the user has selected like this:
let formatter = DateFormatter()
formatter.dateFormat = "HH:mm"
formatter.string(from: timeStamp)
Now I have a very weird bug where sometimes time output will be correct (time will be displayed in UTC+2) and sometimes it'll be incorrect (time will be displayed in UTC+1) and I have absolutely no idea what could be causing this.
Example 1 (correct output):
User selects: May 26, 2020 - 18:38
Date ISO output: "2020-05-26T16:38:00Z"
DateFormatter output: "18:38"
This is the correct output
Example 2 (wrong output):
User selects: March 26, 2020 - 18:38
Date ISO output: "2020-03-26T16:38:00Z"
DateFormatter output: "17:38"
This is not the correct output. Time should be 18:38 like in the above example.
Someone please tell me how is this possible? Literally the only difference is user picked March instead of May (different month) and that for some reason confuses the DateFormatter, so Time output is in a different timezone.
I am using SwiftDate to work with dates in general.
Set correct formatter.locale, you can try Locale(identifier: "en_US_POSIX") or try to use formatter.timeZone property. Maybe TimeZone.current or TimeZone(secondsFromGMT: 0) will fix your problem
That is probably because in May daylight saving is in effect and the difference to UTC changes from +1 to +2 hours
You can use the current TimeZone and add configure your DateFormatter with it
let timezone = TimeZone.current
dateFormatter.timeZone = timezone
That should make sure that you always use the same timezone that is currently used by your device

How to set timezone on a UIDatePicker?

Is there any way to set a UIDatePicker's timezone to mine (e.g. GMT+3)?
I have tried a lot of solutions on the internet, yet none work.
This is from the Apple docs:
Configuring a Date Picker The configuration of a date picker is
determined by the datePickerMode property, whose value you can set
programmatically or in Interface Builder. For modes that include date
or time values, you can also configure the locale, calendar, and time
zone information as appropriate. The date picker uses that information
when formatting date and time values for the current user, and
defaults to the device’s locale, calendar and time zone. The date
property represents the currently selected date in the form of an
NSDate object, which is calendar and time zone agnostic.
You can set the time zone by configuring the date picker. TimeZone.current will initialise a TimeZone object with the devices current time zone. You can also configure the calendar or locale if needed (though they default to the current device setting).
var picker = UIDatePicker()
picker.calendar = Calendar.current
picker.locale = Locale.current
picker.timeZone = TimeZone.current
You can retrieve the current date with the picker.date property. This can also be set programmatically to animate the date picker to that value.
You can use the date from the datepicker separately as well. You need a date formatter to apply calendar and timezone information:
let date = picker.date
let formatter = DateFormatter()
// Optionally set calendar, timezone etc on formatter
print(formatter.string(from: date))
#IBAction func onValueChanged(_ sender: UIDatePicker) {
print(sender.date.description(with: .current))
}
Reference:
Swift | iOS | XCode - UIDatePicker timezone problem fix
https://www.youtube.com/watch?v=_B9TyvFugy8

Issue with 24hour date format

I am trying to convert Date object in string using DateFormatter but I am getting some weird behavior. I have a timestamp value (1513356296) which I want to convert in 24hour format along with date and timeZone (My current is -0800). Here is my code:
let date = Date(timeIntervalSince1970: Double(1513356296))
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
dateFormatter.timeZone = TimeZone(secondsFromGMT: -(8*3600))
dateFormatter.locale = Locale.current
I am expecting a result value of 2017-12-15T08:44:56-0800 but I am getting 2017-12-15T8:44:56-0800. Everything is same except the hour value. The hour value is 8 instead of 08.
This is not happing with all the test, it happened in only one device and rest are fine.
I also tried by checking if hour value changes if I change device time setting to 12hour format from 24hour format to see what I get for HH and it was always giving me 08 in my case. Only one user was facing this issue.
What's wrong with my code? or is there something wrong with HH I am using?

Display Year, Month and Date in sequence on DateTimePicker iOS

Here is my situation, Current Date picker is showing date, month and year in sequence of Date, Month and Year OR Month, Date and Year. But I want to display this sequence as Year first then Month and at last Date.
I searched a lot but same question I found in Javascript but not in iOS, I also searched in Apple Documentation but I didn't find any solution.
How can I achieve this sequence Year, Month and Date? If there any property or method available for DateTime Picker? OR Do I need to use custom picker? if any then which?
Thanks.
The order of year, month and day is depending on the picker's locale.
Eg.
datePicker.locale = NSLocale(localeIdentifier: "zh_TW")
will have different order from
datePicker.locale = NSLocale(localeIdentifier: "en_US")

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