Landeron caliber 185 is Swiss movement from 1950’s.
Functions: 2 registers on the dial – 60 seconds, 30 or 45 minutes, sub second, cam switched, day, date and month indication.
Manual-winding movement with 17 jewels
f = 18000 A/h
Power reserve: 42 hours
Diameter: 31.0 mm
More information:
Chronograph 185 is the same as caliber 148, with the addition of a calendar device. 
Disassembling:
To gain access to the calendar device, it is necessary first of all to go through operations 1 to 6 for desassembling the chronograph mechanism, after which the device can be disassembled easily.
Assembling:
The device is equally easy to assemble, but the following special points should be taken info account: day star driving wheel 2560 (see diagram) should be placed with its pin F on the line joining the center of the movement and the center of the wheel. Date star driving wheel 2556 should be placed with its large hole G on the line joining the center of the movement and the center of the wheel.
Working and setting of calendar:
After having fitted the dial, turn the winding stem until the day disk jumps forward; fit the date hand, then the hour and minute hands, making sure that they point to 12, and lastly the second hand; then, with the hammer pressed against the hearts by means of the zero action pusher, fit the sweep second hand and the minute-recording hand. Set the watch to the correct time, then set the calendar to the correct date by means of the pushers, remembering that the hands have been set to zero hours. Do not use the pushers to work the calendar between 10 p. m. and 2 a. m., when the automatic “jumping” takes place.
In this caliber, the calendar pushers are fitted in the side of the case; pusher A works the date hand, pusher B the day disk and pusher C the month disk.
Other links:
Landeron caliber 185 watch parts
