As my friend said, I also don't understand the role of the chronograph in mine. Pressing the top button makes it go backwards, pressing the bottom button makes it go forward. If you press it again, it returns after making 2 cycles in the position it was, depending on the time. The 3 cycles basically show the same time.
Update: It is definitely not a chronograph and by pressing the buttons, you adjust the time. I couldn't figure out how to adjust the minutes and it seems like you can't adjust them.