Time.realtimeSinceStartupAsDouble

Description

The real time in seconds since the game started (Read Only). Double precision version of realtimeSinceStartup.

This offers more precision than a float or single value, particularly over extended periods of real-world time. In almost all cases, use the realtimeSinceStartupAsDouble equivalent over realtimeSinceStartup. In almost all cases you can and should use Time.timeAsDouble instead.

Using realtimeSinceStartupAsDouble is useful if you want to set Time.timeScale to zero to pause your application, but still want to be able to measure time somehow. In Editor scripts, you can also use realtimeSinceStartupAsDouble to measure time while the Editor is paused.

realtimeSinceStartupAsDouble returns time as reported by the system timer. Depending on the platform and the hardware, it might report the same time even in several consecutive frames. If you're dividing something by time difference, take this into account (for example, time difference might become zero).

using UnityEngine;
using System.Collections;

// An FPS counter.
// It calculates frames/second over each updateInterval,
// so the display does not keep changing wildly.
public class ExampleClass : MonoBehaviour
{
    public float updateInterval = 0.5F;
    private double lastInterval;
    private int frames = 0;
    private float fps;
    void Start()
    {
        lastInterval = Time.realtimeSinceStartupAsDouble;
        frames = 0;
    }

    void OnGUI()
    {
        GUILayout.Label("" + fps.ToString("f2"));
    }

    void Update()
    {
        ++frames;
        double timeNow = Time.realtimeSinceStartupAsDouble;
        if (timeNow > lastInterval + updateInterval)
        {
            fps = (float)(frames / (timeNow - lastInterval));
            frames = 0;
            lastInterval = timeNow;
        }
    }
}