Not all perpetual calendars are made equal - we know that. The special ones are not only a technical feat but also easy to read - enter the Lange 1 Tourbillon Perpetual Calendar.
Perpetual calendars unlike the annual calendar counterparts knows the numbers of days in a month and correctly jumps to the right date at the switch over. For 11 months in a year, the days will either be 31 or 30 days. But for February, it will be 28 days for three years and during the leap year, will have 29 days. The perpetual calendar mechanism takes into consideration the leap year and ensures that for that one year, the date display jumps from 28 to 29 and from 29 to 01 as with the case of the Lange which has the big date function.
So much has been said about the perpetual calendar in a mechanical timepiece but all said and done, the perpetual calendar has to be, first and foremost, legible. A few timepieces have got it right - the Moser Perpetual One for one. And with the Lange 1 Tourbillon Perpetual Calendar, the manufacture Lange has another winner.
The off-centre Lange 1 layout with a clearly intuitive dial layout. Lange 1 is perhaps the most well known off-centre dial timepiece that is so symmetrically proportionate. The day, date, month, and moon phase are very well laid out. Two other indicators are the leap year and the day/night indicator within the time dial.
The display of the Lange 1 Tourbillon Perpetual Calendar is laid out in a rather "unconventional" way. Typical perpetual calendars will use the sub-dials to display the days, months etc. But with the Lange TPC, the unique layout allows the owner a clear view of the timepiece - uncluttered view. (Pardon the smudges on the sapphire glass - my bad).
The outer ring revolves anti-clockwise displaying the month of the year. At the 8 to 10 o'clock displays the day of the week and the Lange big date is unmistakable. The 7 displays the moon phase. Right at the 6 is the leap year display. The dial is clean and the indicators can be clearly read.
Turn the rotor to the other side and it reveals the Tourbillon. As with the Datograph Perpetual Tourbillon, the Tourbillon has a stop seconds mechanism.
A Lange 1 is a Lange 1. Only that the people at Glashutte made it a more iconic - with a stop second Tourbillon and adding on a Perpetual Calendar complication. Well done again!