💩⌛️ example

💩⌛️.swift

extension DateFormatter {
    
    private enum DateFormatters {
        static var yearMonthDayFormat: String = "yyyy%@MM%@dd"
        static var dayMonthYearFormat: String = "dd%@MM%@yyyy"
        static var chatDateFormat: String = "EEEE d'%@' MMMM"
        
        static var yearMonthDayFormatters: [Separator : DateFormatter] = [:]
        static var dayMonthYearFormatters: [Separator : DateFormatter] = [:]
        static var dateFormatters: [String : DateFormatter] = [:]
        
        static func dateFormatterWithFormat(format: String, separator: Separator) -> DateFormatter {
            let formatter = DateFormatter()
            formatter.dateFormat = String(format: format, separator, separator, separator)
            return formatter
        }
        
        static func yearMonthDayFormatterWithSeparator(separator: Separator) -> DateFormatter {
            if let formatter = yearMonthDayFormatters[separator] {
                return formatter
            } else {
                let formatter = dateFormatterWithFormat(yearMonthDayFormat, separator: separator)
                
                yearMonthDayFormatters[separator] = formatter
                
                return formatter
            }
        }
    }
    
    static func yearMonthDayFormatter(separator: Separator) -> DateFormatter {
        return DateFormatters.yearMonthDayFormatterWithSeparator(separator)
    }
}