My high time score isn't working

Questions & Answers
1

I have a most time survived scoring system but there is something wrong with my timer. When i reach a new high time it shows like ss:ss instead of mm:ss (like 29:29 instead of 00:29) and things getting more interesting, after i restart the game timer works properly(shows like 00:29). Please help me guys. There is my code:

 private void Start()
    {
        startTime = Time.time;
        float gameTimer = Time.time - startTime;
        string minutes = Mathf.Floor(gameTimer / 60).ToString("00");
        string seconds = (gameTimer % 60).ToString("00");

        mostTimeSurvived.text = PlayerPrefs.GetFloat("HighTime").ToString(string.Format("{0:00}:{1:00}", minutes, seconds));
    }

        public void Finish()
        {
        finished = true;
        float gameTimer = Time.time - startTime;

        string minutes = Mathf.Floor(gameTimer / 60).ToString("00");
        string seconds = (gameTimer % 60).ToString("00");
        

        if (PlayerPrefs.GetFloat("HighTime") < gameTimer)
        {
            PlayerPrefs.SetFloat("HighTime", gameTimer);
            mostTimeSurvived.text = gameTimer.ToString(string.Format("{0:00}:{1:00}", minutes, seconds));
        }
    }
2

You could really simplify your code to something like this.

Without Pausing

    private DateTime sessionStartTime;
    private TimeSpan gameLength;

    void Start()
    {
        sessionStartTime = DateTime.Now;
    }

    void Update()
    {
        gameLength = DateTime.Now - sessionStartTime;
        var gameLengthText = gameLength.ToString(@"mm\:ss");
    }

NOTE

If you have a pausing mechanism this wouldn’t work but there are ways to deal with that too, which would be more manageable.

i.e. just storing a collection of time spans for each (or if memory is a concern taking the sum of the last sessions and the current one) session and then taking the sum of them.

With Pausing

     private DateTime sessionStartTime;
    private TimeSpan gameLength;
    private bool IsPaused = false;

    void Start()
    {
        sessionStartTime = DateTime.Now;
    }

    void Update()
    {
        if(!IsPaused)
        {
            var lastSessionLength = DateTime.Now - sessionStartTime;
            gameLength += lastSessionLength;
        }  

        sessionStartTime = DateTime.Now;   
        if(Input.GetKeyDown(KeyCode.Space)) IsPaused = !IsPaused;

        var gameLengthText = gameLength.ToString(@"mm\:ss");
    }

Edit: Just noticed that you were wanting to evaluate on every frame so updated the code.