Lerp incorect count

Hello everyone. I got stuck on a very strange problem. Lerp doesn't count correctly.
The goal is to count from "startValue" to "endValue" for "lerpDuration" seconds.
The code is clear enough.
I tried different combinations with Mathf.Lerp, Vector3.Lerp, Vector2.Lerp but the result is additional one second more each time. Does anyone have idea where this error is coming from?
Final Result:
Debug - START 7:57:46:392
Debug - END 7:57:48:793
or
Debug - START 8:19:14:147
Debug - END 8:19:16:559
....?

void Start()
{
timeElapsed = 0;
lerpDuration = 1;
startValue = 0;
endValue = 10;
lerpCount = startValue;
Debug.Log("START " + DateTime.Now.ToString("h:mm:ss:fff"));
allowCount = true;
}
void Update()
{
if (!allowCount) return;
if (timeElapsed < lerpDuration)
{
lerpCount = Mathf.Lerp(startValue, endValue, timeElapsed / lerpDuration);
timeElapsed += Time.deltaTime;
}
else
{
Debug.Log("END " + DateTime.Now.ToString("h:mm:ss:fff"));
allowCount = false;
}
}

 

https://forum.unity.com/threads/using-code-tags-properly.143875/

 

I'm sorry

 

Hi,
How about putting some extra Debug.Logs in the code to see how many times the loop is running, and how the values changes in each loop?

 

You can edit your post to change it

Unity runs all Start() functions before it begins to run Update() functions. So you're recording your start time in Start(), Unity is going off doing lots of other work, then later, starting your actual timer in Update() by which time you've got a additional time on your clock.

Put the start timer code in Update() behind a GetKeyDown(), wait until everything has been initialized, then start the timer. Your results should be regular now. For good measure, set timeElapsed = 0 when you end timing so you can try it without having to restart every time a timer finishes.