Not being “in-house” does not mean that the movement custom modifications or finishing done by Breitling, it just means that the base movement architecture/framework was not designed and manufactured by them.
Setting the Time and Date:
If the watch has a screw-in crown (as most Breitling watches do), unscrew the crown to be in hand-winding position (Breitling calls this position 1).
Pull the crown out one click (Breitling calls this position 2).
Turn the crown counterclockwise to advance the date forward.
For accurate time/date setting, set the date to the day before the current date. Use time-setting mode to make the date flip to the current date and then proceed to set the time accordingly.
Pull the crown out another click (position 3) to time-setting mode.