What time is it? Probably one of the most frequently asked questions but simply posing the question does not guarantee receiving a correct answer. These days watches are fairly accurate so what makes a watch that is not covered in diamonds worth over a million dollars when you can buy an attractive, reasonably accurate watch for a few hundred dollars? The answer seems to be in the complexity of the design and something called “complications” which simply put, are the different bits of information the watch can provide besides telling you the time. They also include features like the tourbillon, which was invented in 1795 and which counters the effects of gravity that make a timepiece imprecise. They're included in high-end designs today as a display of virtuosity,

The Patek Philippe Calibre 89 US$6.000.000 estimated value

The Patek Philippe Calibre 89 is a commemorative pocket watch created in 1989, to celebrate the company's 150th anniversary. Declared by Patek Philippe as "the most complicated watch in the world", it weighs 1.1 kg, exhibits 24 hands and has 1,728 components in total, including a thermometer and a star chart. Made from 18 carat (75%) gold, it has an estimated value of $6 million, and took 5 years of research and development, and 4 years to manufacture. Four watches were made; one in white gold, one in yellow gold, one in rose gold and one in platinum.

The Aeternitas Mega 4 $2.700,000

36 complications, 25 of them visible, 1,483 components, a 1000-year calendar, a price tag of 2.7 million dollars, and 5 years' work: what others have simply dreamed of, Franck Muller has made a reality! Never has the Maison de Haute Horlogerie better deserved its name of "Master of Complications", pulverising the record number of complications ever housed in a single wristwatch. The challenge for the Master Watchmakers of Genthod was enormous: how to embed all the complications known to this day in a watch that was designed to be worn. The Aeternitas movement served as a base, while the Mega 4 represents the apotheosis of the art of watch making with its grand and small Westminster chime striking-work, the only one available on the market with a tourbillon visible on the dial. Added to this are a minute repeater, a mono-pushpiece split-seconds chronograph, a perpetual calendar secular, and an equation of time which only varies by 6.8 seconds per lunar month, the equivalent of one day every thousand years! Although the first piece of this exceptional, limited series was presented to an American collector at a ceremony in Monaco.

Vacheron Constantin Tour de l’Ile, $1,500,000 US dollars

The Swiss watchmaker Vacheron Constantin marked its 250th anniversary in 2005 with the year’s most expensive watch. Its name refers to one of the historical sites of the venerable company, located next to the current Maison Vacheron Constantin on the Quai de l’Ile. At $1.5 million, that was the most expensive watch that year.

This expensive watch is also the most complicated double-face watch, and only produced in a limited edition of seven. Tour de l’Ile is made with a totally original combination of horological complications and astronomical indications composing a list of sixteen different points including a minute repeater, sunset time, perpetual calendar, second time zone, a tourbillon device, the equation of time and the representation of the night sky.

Patek Philippe Sky Moon Tourbillon 5002 P US$1,500,000

The platinum 5002 P is a production watch, they don’t make many of them but it is still a production watch rather than a one-of.

It is composed of 686 parts, some of which are microscopically small. It is double faced with celestial movements. It has a 55 jewel movement, 48 hour power reserve, manual winding and comes with a sapphire crystal and a black crocodile leather band. Don't get it wet; the case protects against humidity and dust only.

Girard Perregaux Opera 3 US$500,000

A watch capable of playing music these days is far from newsworthy, but one that does it via purely mechanical means? Well now that’s interesting. This is the Opera Three musical watch from Girard-Perregaux which features an extremely tiny music box inside composed of a ‘keyboard’ with 20 blades that’s played by a spinning drum featuring 150 hand-mounted pins. So instead of some annoying digital beep at the top of the hour, you can enjoy Tchaikovsky or Mozart. The watch, with its platinum case and alligator skin strap, was actually released way back in 2002 and is on the brink of becoming a collector’s item with prices going up as a result.