1. If you keep this moon-phase, perpetual calendar, retrograde behemoth running continuously it won't need adjusting until 2

2. Patek Philippe platinum and diamond-set perpetual calendar chronograph wristwatch with moon-phases and leap-year indication, circa 200 REF 5971P.

3. Yellow gold hunter case, movement with simple chronograph, 48-month perpetual calendar, phases and age of the moon[http://Sentencedict.com], minute repeater.

4. Patek Philippe Platinum And Diamond-Set Perpetual Calendar Chronograph Wristwatch With Register, Moon-Phases And Leap Year Indication, c. 19 Ref. 3990P.