ios – How do i deal with the issue that the nation is utilizing 24h time system however the telephone is about to 12h time system

Right here is my code 👇

In my utility, when the person creates an occasion, the occasion time is proven to the person. Nonetheless, if the telephone is in a 12 time zone and is in a language aside from English, this time returns null.

func utcToLocal(dateStr: String) -> String? {
    let isCurrentDevice12HoursFormat = DateFormatter.dateFormat(fromTemplate: "j", choices: 0, locale: Locale.present)?.vary(of: "a") != nil
    let isDateStr12HoursFormat = dateStr.final == "M"
    let dateFormatter = DateFormatter()
    dateFormatter.locale = Locale(identifier: isDateStr12HoursFormat ? "en_US_POSIX" : "en_UK_POSIX")
    dateFormatter.dateFormat = isDateStr12HoursFormat ? "yyyy-MM-dd' 'h:mm:ss a" : "yyyy-MM-dd' 'HH:mm:ss"
    dateFormatter.timeZone = TimeZone(abbreviation: "UTC")
    
    if let date = dateFormatter.date(from: dateStr) {
        dateFormatter.timeZone = TimeZone.present
        dateFormatter.dateFormat = isCurrentDevice12HoursFormat ? "yyyy-MM-dd' 'h:mm:ss a" : "yyyy-MM-dd' 'HH:mm:ss"
        return dateFormatter.string(from: date)
    }
    return nil
}