Formatting a Date and Time in Swift

Question

I have this time format 2022-01-09T19:04:16 obtained from an API. I would like to show a readable time from this string and also, possibly the difference from given time and current time.

I cannot find a suitable format for this. Can someone please assist? I tried to substring the retrieved value as below, but, this is not what I want.

let str = "2022-01-09T19:04:16" print(str.suffix(8)) //prints 19:04:16

Answer 1

You can convert the String to Date and handle all operations that you would like to do with it.

1. As the input format is not a standard one I assume that we are using UTC.
2. If the input changes the function will throw an error without breaking most of your code.

enum DateFormattingErrors: Error {
    case invalidFormat
}

func formatDate(_ from: String) throws -> Date {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
    dateFormatter.timeZone = TimeZone(abbreviation: "UTC")

    guard let date = dateFormatter.date(from: from) else {
        throw DateFormattingErrors.invalidFormat
    }
    
    return date
}

func UTCFormattedDate(_ from: Date, withDate: Bool) -> String {
    let utcDateFormatter = DateFormatter()
    if withDate {
        utcDateFormatter.dateStyle = .medium
    }
    utcDateFormatter.timeStyle = .medium
    utcDateFormatter.timeZone = TimeZone(abbreviation: "UTC")
    return utcDateFormatter.string(from: from)
}

do {
    let date = try formatDate("2022-01-09T19:04:16")
    print(Date().description)
    print(date.timeIntervalSinceNow) //Time difference between given date and current date
    print(UTCFormattedDate(date, withDate: false)) // Better representation of date
} catch {
    print(error)
}

Output

2022-01-10 10:09:03 +0000  //CurrentDate
-54287.22359800339         //Time difference current and given
7:04:16 PM                 //Formatted date