====== A. Lange & Söhne 1815 Rattrapante Perpetual Calendar ======

{{wst>image_cr|A. Lange & Söhne|1815 Rattrapante Ewiger Kalender Platin|A. Lange & Söhne 1815 Rattrapante Perpetual Calendar, platinum}}
{{wst>image_cr|A. Lange & Söhne|1815 Rattrapante Ewiger Kalender Rotgold|A. Lange & Söhne 1815 Rattrapante Perpetual Calendar, red gold}}
{{wst>image_cr|A. Lange & Söhne|1815 Rattrapante Ewiger Kalender Weißgold||A. Lange & Söhne 1815 Rattrapante Perpetual Calendar, white gold}}

{{wst>image_cr|Lange|L101.1}}

**1815 Rattrapante Perpetual Calendar** is a luxury wristwatch by [[A. Lange & Söhne]].

This model was introduced [[2013]]. It combines two sophisticated, classic [[complication]]s in one wristwatch: a [[chronograph]] with [[rattrapante]] function and a [[perpetual calendar]] with [[moon phase indication]]. 

The dial is made of solid silver, and solid red gold for the [[white gold]] model released in [[2023]]. The hands are made of rhodium-plated gold, blued steel, and gold-plated steel.

While the rattrapante chronograph masters the measurement of various time intervals down to the fraction of a second, the technical mastery of the perpetual calendar lies in its "long-term memory". The complex and proverbial forward-looking mechanism ensures the exact representation of the date, day of the week and month every day for decades, even taking leap years into account. Only on March 1 [[2100]] does the calendar display have to be corrected by one day, because then, according to the regulations of the [[Gregorian calendar]], the [[leap year]] no longer applies.

The [[moon phase]] display is also programmed for the long term. It shows the synodic orbital period of the earth's satellite so exactly that it has to be corrected by one day only in 122.6 years.

<WRAP ud ud_mod>
**Reference:**
  * 421.025 [[platinum]]
  * 421.032 [[red gold]]
  * 421.056FE [[white gold]] ([[2023]])

**Movement:**
  * [[Manual winding]] [[manufacture movement]] [[Lange L101|L101.1]], 21.600 A/h
  * Precision adjustment: [[Screw balance]]
  * [[Perpetual calendar]], [[rattrapante]]
  * 43 [[jewels]], including 4 in screwed gold [[chaton]]s
  * Diameter: 32.6 mm; Height: 9.1 mm
  * 631 components
  * Power reserve 42 hours

**Case:**
  * 18 ct [[red gold]], white gold or [[platinum]]
  * Ø 41.9 mm, height 14.7 mm
  * [[Sapphire crystal]]
  * Caseback with [[sapphire crystal]] sighting window

**Dial:**
  * Solid silver, argenté
  * Hands in rhodinated gold, blued steel and gilded steel

**Functions:**
  * Hours, minutes
  * [[Small seconds]] at 6 h
  * Central [[chronograph]] seconds and [[rattrapante]] seconds
  * 30 [[rattrapante]] minutes at 12 h
  * [[Perpetual calendar]] 
  * Day of week and [[hand date]] at 9 h
  * Month and leap year indication at 3 h
  * [[Moon phase indication]] at 6 h
  * [[Power reserve indicator]] at 12 h

**Bracelet:**
  * Crocodile leather strap
</WRAP>

{{tag>Watch_models Chronographs Rattrapante Watches_with_moon_phase Watches_with_perpetual_calendar A._Lange_&_Söhne_models A._Lange_&_Söhne_1815_models}}