Here is a review of UN GMT Minus Big Date Review
The Ulysse Nardin GMT +/- Dual Time Big Date watches are outstanding timepieces for those who travel frequently or have business dealings across multiple timezones. The key to the outstanding functionality of the Ulysse Nardin GMT +/- Dual Time Big Date watch is the unique selfwinding UN-22 movement, which incorporates an independently adjustable hour hand, in conjunction with a home time display and a large date.
Since minutes and seconds are the same in almost all of the major time zones, it is an advantage if a watch's hour can be adjusted for various time zones without disturbing the seconds or minute hand. The precise selfwinding mechanism of the UN-22 movements allows just this, and the procedure for enacting the change is as simple as pushing one of the two buttons on the left side of the case, the upper to advance, and the lower to subtract, according to the location or travel plans of the wearer. To ensure that the time back home can easily be kept track of, the Ulysse Nardin GMT +/- Dual Time Big Date watch features a window display that shows a second time zone, in a 24-hour format. Further innovation within this mechanism is provided by the strikingly visible large date display.
Not only easy to read, this innovative wheel-based date construction allows adjustment in both the forwards and backwards direction, a convenient feature whose mechanics are protected by a patent. The construction of the GMT +/- Dual Time Big Date watch is robust, and the carefully secured caseback, screwed down crown, and gasketed pushpieces enable the watch to resist water intrusion to a depth of 100 meters. But, perhaps most importantly, the Ulysse Nardin GMT +/- Dual Time Big Date watch is beautiful, its elegantly sculpted 40 mm case in warm 18K rose gold or stainless steel demonstrating fine finish and rich detail, a quality echoed by the dials whose intricate guilloche patterns in an array of finishes, such as silvered, or anthracite speak well of the fine craftsmanship proudly practiced by the house of Ulysse Nardin.