Issue in formatting date string Swift 3

Question

I need to convert the following date string in to a Date in Swift 3.

Fri Dec 09 16:18:43 AMST 2016

Here is the code that i have been using, but it's getting cash on this particular date string conversion. (This date was logged on Android using new Date().toString() method.)

static func formatDate(date: String) -> String {
        let dateFormatter = DateFormatter()

        dateFormatter.timeZone = TimeZone(secondsFromGMT: 0)
        dateFormatter.dateFormat = "EEE MMM dd HH:mm:ss zzz yyyy" 
        //Works for "Fri Sep 16 10:55:48 GMT+05:30 2016"

        var myDate = dateFormatter.date(from: date)
        // My date returns nil on "Fri Dec 09 16:18:43 AMST 2016"

        dateFormatter.dateFormat = "dd/MM/yyyy"
        return "\(dateFormatter.string(from: myDate!))"
    }

There are both type of strings in the database. I tried with various types of Timezone formats (z/zz/zzz/zzzz/zzzzz) but always myDate returns nil.

Any help would be appreciated. Thanks In Advance.

Try using without time zone if this dose not wok try then re arranging your date format to "EEE MMM dd HH:mm:ss zzz yyyy" and dateFormatter.timeZone = NSTimeZone.local or try setting Local.current — Darshan Mothreja, Sep 01 '17 at 11:39

nyg · Accepted Answer · 2017-09-01T12:56:11.047

Apple doc for TimeZone(abbreviation:):

In general, you are discouraged from using abbreviations except for unique instances such as “GMT”. Time Zone abbreviations are not standardized and so a given abbreviation may have multiple meanings.

Does AMST represents "Amazon Summer Time" (UTC-3) or "Armenia Summer Time" (UTC+5)? See: https://www.timeanddate.com/time/zones

That's probably why it can't detect the proper timezone to use.

Solutions I can propose:

If you know which timezone AMST is:
- replace AMST by UTC-3 or UTC+5 in the date string
- remove AMST from the date string and use dateFormatter.timeZone = TimeZone(secondsFromGMT: -3 or 5 * 3600)
Have your source output a more precise timezone.

Note the following code, where AMST is understood correctly:

let df = DateFormatter()
df.locale = Locale.init(identifier: "pt_BR") // assuming AMST is Amazon Summer Time (UTC -3)
df.dateFormat = "HH:mm:ss z"

print(df.date(from: "16:18:43 AMST")) // Optional(2000-01-01 19:18:43 +0000)

But as soon as you include English day or month names (e.g. Fri or Dec) it will produce nil (because they aren't in Portuguese).

Issue in formatting date string Swift 3

1 Answers1