private static class TimeExtensions
        {
            public static string FormatShortTime( TimeSpan time )
            {
                string result = string.Empty;
                if (time.Days != 0)
                    result += $"{time.Days} д. ";

                if (time.Hours != 0)
                    result += $"{time.Hours} ч. ";

                if (time.Minutes != 0)
                    result += $"{time.Minutes} м. ";

                if (time.Seconds != 0)
                    result += $"{time.Seconds} с. ";

                return result;
            }

            public static string FormatTime( TimeSpan time )
            {
                string result = string.Empty;
                if (time.Days != 0)
                    result += $"{Format( time.Days, "дней", "дня", "день" )} ";

                if (time.Hours != 0)
                    result += $"{Format( time.Hours, "часов", "часа", "час" )} ";

                if (time.Minutes != 0)
                    result += $"{Format( time.Minutes, "минут", "минуты", "минута" )} ";

                if (time.Seconds != 0)
                    result += $"{Format( time.Seconds, "секунд", "секунды", "секунда" )} ";

                return result;
            }

            private static string Format( int units, string form1, string form2, string form3 )
            {
                var tmp = units % 10;

                if (units >= 5 && units <= 20 || tmp >= 5 && tmp <= 9)
                    return $"{units} {form1}";

                if (tmp >= 2 && tmp <= 4)
                    return $"{units} {form2}";

                return $"{units} {form3}";
            }
        }