confused, passing tuple?

// fixes times like more than 60 seconds
        //          int, int, int
        public (int, int, int) Fix(int hours, int minutes, int seconds)
        {
            return realFix(hours, minutes, seconds);
        }
        //          string
        public string Fix(string timeString)
        {
            return ConvertVariablesToTimeString(realFix(ConvertTimeStringToVariables(timeString)));
        }
// NOTE: maybe 1 convert method instead of 2?
// Converts Time String to variables to use
public (int, int, int) ConvertTimeStringToVariables(string timeString)
{
    string[] times = timeString.Split(':');
    int hours = int.Parse(times[0]);
    int minutes = int.Parse(times[1]);
    int seconds = int.Parse(times[2]);
    return (hours, minutes, seconds);
}

// Converts Variables to Time String
public string ConvertVariablesToTimeString(int hours, int minutes, int seconds)
{
    return $"{hours}:{minutes}:{seconds}";
}
public (int, int, int) realFix(int hours, int minutes, int seconds)
        {
            while (seconds >= 60)
            {
                seconds -= 60;
                minutes++;
            }
            while (minutes >= 60)
            {
                minutes -= 60;
                hours++;
            }
            return (hours, minutes, seconds);
        }

// fixes times like more than 60 seconds
        //          int, int, int
        public (int, int, int) Fix(int hours, int minutes, int seconds)
        {
            return realFix(hours, minutes, seconds);
        }
        //          string
        public string Fix(string timeString)
        {
            return ConvertVariablesToTimeString(realFix(ConvertTimeStringToVariables(timeString)));
        }
// NOTE: maybe 1 convert method instead of 2?
// Converts Time String to variables to use
public (int, int, int) ConvertTimeStringToVariables(string timeString)
{
    string[] times = timeString.Split(':');
    int hours = int.Parse(times[0]);
    int minutes = int.Parse(times[1]);
    int seconds = int.Parse(times[2]);
    return (hours, minutes, seconds);
}

// Converts Variables to Time String
public string ConvertVariablesToTimeString(int hours, int minutes, int seconds)
{
    return $"{hours}:{minutes}:{seconds}";
}
public (int, int, int) realFix(int hours, int minutes, int seconds)
        {
            while (seconds >= 60)
            {
                seconds -= 60;
                minutes++;
            }
            while (minutes >= 60)
            {
                minutes -= 60;
                hours++;
            }
            return (hours, minutes, seconds);
        }