Animation lengths doesn't match

Hello dear friends!
Why is animation length doesn’t match its real value?
I have animation clip for 0.35 sec. But in inspector it says this animation lasts for 0.583.

Because of that when I try to play animation back (with -1 speed) a have some pause for 0.233 sec.
It’s not what I want…

84869-2016-12-28.png

I have animation clip for 0.35 sec

No, that’s not the way you read the Animation panel.

The last keyframe is located at the point 0:35 meaning, it’s the 35th frame, and since the animation is running at 60 FPS (60 samples), you are still within the 1st second of animation (thus : 0).

If you divide 35 by 60, you get … 0.58333, the length of your animation clip.

Yes, I know, this is not obvious.