15500’s calendar dial

[SepWind]

Hello everyone! I would like to get your opinions.

This is my first mechanical watch. I am very confused by the calendar dial that turns like this.

Starting at 16:30 each day, the calendar dial slowly turns anti-clockwise, reaching its extreme position at around 18:20. At this point, the topmost part of the numerals in the calendar dial is obscured by the calendar window. The dial jumps back to its correct position at around 18:23.

Is this normal?