quattro[Moderator]
20231
Audemars Piguet Dual Time
This layout of the dual time complication (with second time zone at 6 o'clock, date at 2 and power reserve at 10) has been used in four collections: Jules Audemars, Millenary, Royal Oak & Royal Oak Offshore.
A day/night indicator was later added between 6 and 7 o'clock: I like it less and have just added two photos at the end for comparison.
Have a great week-end.
1/ JULES AUDEMARS (ref. 25685 with 36mm case & caliber 2129 or 2229)
Ref. 25685BA (yellow gold)

credit: timeless vintage watches (& Amsterdam vintage watches for the case profile)
Ref. 25685PT with blue dial (platinum)

credit: the keystone
Ref. 25685PT with white dial (platinum)

credit: the keystone
Ref. 25685BC.00.A002XX.06 with brown or "Havana" dial (white gold)

NB: on Bulang & Sons, from which these photos come, this watch is presented as Platinum, which is in contradiction with the extract, and the dial is said to have been "originally blue but has now changed colour to stunning shades of orange and purple"
Ref. 25685BC with black dial & diamond indexes (white gold)

credit: Amsterdam vintage watches
2/ MILLENARY (ref.
25778 with 41x39mm case & cal. 2229)
Ref. 25778OR (rose gold)

credit: dreamwatch.de
Ref. 25778BC.OO.D001CR.01 (white gold)

credit: Zeitauktion
2/ ROYAL OAK ref. 25730 (36mm case & caliber 2229)
Ref. 25730ST with white dial (steel)

credit: hairspring
Ref. 25730ST with "Yves Klein" blue dial (steel)

credit: tokant
Ref. 25730ST with tropical blue dial (steel)

credit: montro

credit: vintage uhren
Ref. 25730SA (yellow gold & steel)

credit: Amsterdam vintage watches
3/ ROYAL OAK OFFSHORE (ref.
25970 with 38mm case & caliber 2229)
Ref. 25970ST.OO.1010ST.01, stainless steel, ‘Hong Kong’ limited edition of 100 pieces (1997) 
credit: quill & pad courtesy of AP Chronicles
Ref. 25970ST with leather strap (steel)

credit: every watch
Ref. 25970OR with black dial & diamond indexes (rose gold)

credit: collector square
Ref. 25970BA/OO/1010BA/01 limited to 20 pieces (yellow gold)

credit: chronext
4/ DIAL WITH DAY/NIGHT INDICATOR
Ref. 26120OR (rose gold, 39mm case & caliber 2329)

credit: first class timepieces
Ref. 26380OR.OO.D088CR.01 (rose gold, 41mm case & cal. 2329)

credit: watchfinder