Am I using Time.deltaTime incorrectly?

I made a simple day counter and it doesn’t count up in unity, yet it doesn’t give me an error. I assume it has something to do with my usage of Time.deltaTime

using UnityEngine;
using System.Collections;

public class DaySystem : MonoBehaviour {

    public int day = 1;
    private float timeOfDay = 0.0f;

    public void Start()
    {
        timeOfDay = Time.deltaTime;
        day = 1;
    }

    private void TimeOfDay()
    {
        if(Time.deltaTime > 1.0f)
        {
            timeOfDay += 1.0f;
        }
    }

    public void DayCounter()
    {
        if (timeOfDay == 25.0f)
        {
            day += 1;
        }
    }
}

It doesn’t give you an error because, well, it doesn’t do anything. You never call the TimeOfDay() or DayCounter() methods anywhere and, even if you did, it’s very difficult to say what they would achieve.

     if(Time.deltaTime > 1.0f)
     {
         timeOfDay += 1.0f;
     }

means “if it took more than 1 second to render the last frame, add one to timeOfDay”…

    if (timeOfDay == 25.0f)
     {
         day += 1;
     }

means “if timeOfDay equals exactly 25f (which it’s very unlikely to do since it’s a floating point value), add one to day”.

You don’t really need to use deltaTime anywhere - just use Time.time if you want to know how long the game has been running. And if you want to increment other counters, you need to do so in a method that gets called - either from Update() or somewhere else.