1022 day date movement question

[Wat-1]

So i purchased this omega day date sold. As for parts or non working and took gamble

So my question is I've been wearing it for the past 3 hours all and is running and keeping time perfectly??? The quick set one the date is a little hit and miss due the gear slipping but ok. the 3 gears one is completely missing looks like a snapped screw my question is what do they actually do lol ?? Thanks

 

[Canuck]

Part of the manual winding system.

 

[Wat-1]

Canuck

Part of the manual winding system.

Thankyou much appreciated