Hi, alex, Dennis.
Dennis - is yours automatic or manual?
There seems to be quite a bit of confusion regarding the movement in the Type XX version of the Breguet alarm wristwatch.
For sure, Breguet has released at least two models of an alarm wristwatch, one of which is based on the Lemania automatic movement which was also used by Omega as their Memomatic in the 1970's -

ref. 3600
The Type XX, on the other hand, is a different model -

ref. 3860
From the position and style of the crowns, I would be tempted to agree that it is a manual A Schild movement, but quite a number of people, who are otherwise reliable about their information, have inconsistently referenced the cal. 579 as manual (Eddie/Malaysia) or automatic (certain well known auction houses, usually reliable Japanese dealers, internet watch trivia guru SSS) An internet dealer from New York described one he had for sale as automatic as well, though his information is not usually reliable. (note the crown and pusher configuration of the Lemania based automatic alarm in the upper picture, as opposed to the two crown design of the lower picture of the XX)
Except for SSS, most others name the cal. 579 as the movement in the Type XX.
Alex, when so many otherwise reliable sources of information are so inconsistent and mutually contradictory, I think it is time to do a little more fact checking...
Regards,
TM