Xcode swift am/pm time to 24 hour format

Question

I am trying to convert a am/pm format time to a 24 hour format time

6:35 PM to 18:35

I tried this piece of code on playground but it doesnt

Answer 1

Swift version 3.0.2 , Xcode Version 8.2.1 (8C1002) (12 hr format ):

func getTodayString() -> String{

        let formatter = DateFormatter()
        formatter.dateFormat = "h:mm:ss a "
        formatter.amSymbol = "AM"
        formatter.pmSymbol = "PM"

        let currentDateStr = formatter.string(from: Date())
        print(currentDateStr)
        return currentDateStr 
}

OUTPUT : 12:41:42 AM

Feel free to comment. Thanks

Answer 2

let calendar = Calendar.current
let hours    = calendar.component(.hour, from: Date())
let minutes  = calendar.component(.minute, from: Date())
let seconds  = calendar.component(.second, from: Date())

Answer 3

Unfortunately apple priority the device date format, so in some cases against what you put, swift change your format to 12hrs

To fix this is necessary to use setLocalizedDateFormatFromTemplate instead of dateFormat an hide the AM and PM

let formatter = DateFormatter()
formatter.setLocalizedDateFormatFromTemplate("HH:mm:ss a")
formatter.amSymbol = ""
formatter.pmSymbol = ""
formatter.timeZone = TimeZone(secondsFromGMT: 0)
var prettyDate = formatter.string(from: Date())

You can check a very useful post with more information detailed in https://prograils.com/posts/the-curious-case-of-the-24-hour-time-format-in-swift

Answer 4

Swift 3 *

Code to convert 12 hours (i.e. AM and PM) to 24 hours format which includes-

Hours:Minutes:Seconds:AM/PM to Hours:Minutes:Seconds

func timeConversion24(time12: String) -> String {
    let dateAsString = time12
    let df = DateFormatter()
    df.dateFormat = "hh:mm:ssa"

    let date = df.date(from: dateAsString)
    df.dateFormat = "HH:mm:ss"

    let time24 = df.string(from: date!)
    print(time24)
    return time24
}

Input

07:05:45PM

Output

19:05:45

Similarly

Code to convert 24 hours to 12 hours (i.e. AM and PM) format which includes-

Hours:Minutes:Seconds to Hours:Minutes:Seconds:AM/PM

func timeConversion12(time24: String) -> String {
    let dateAsString = time24
    let df = DateFormatter()
    df.dateFormat = "HH:mm:ss"

    let date = df.date(from: dateAsString)
    df.dateFormat = "hh:mm:ssa"

    let time12 = df.string(from: date!)
    print(time12)
    return time12
}

Input

19:05:45

Output

07:05:45PM

Answer 5

Here is code for other way around

For Swift 3

 func amAppend(str:String) -> String{
    var temp = str
    var strArr = str.characters.split{$0 == ":"}.map(String.init)
    var hour = Int(strArr[0])!
    var min = Int(strArr[1])!
    if(hour > 12){
        temp = temp + "PM"
    }
    else{
        temp = temp + "AM"
    }
    return temp
}