Käekellade

Käekellad are portable timekeeping devices worn on the wrist. The Estonian term Käekellad derives from käsi (hand) and kell (clock or watch). A typical wristwatch consists of a movement inside a case, a dial with hour and minute hands (and often a second hand), and a strap or bracelet.

Historically, early portable timepieces appeared in the 16th–17th centuries and evolved from pocket watches. Wristwatches gained widespread use in the early 20th century, especially among military personnel during World War I. The quartz crisis of the 1960s–1980s transformed production and affordability, followed by the rise of digital and smartwatches in the 2010s and beyond.

Today Käekellad include several main types: mechanical watches (manual-winding and automatic), quartz watches powered by batteries and a quartz oscillator, and digital or smartwatches with electronic displays and connectivity. Mechanical watches store energy in a mainspring and regulate time with an escapement; quartz watches rely on a crystal oscillator for accurate timekeeping.

Common features include date indications, chronographs, and varying levels of water resistance. Higher-end models may add complications such as moon phases or tourbillons. Key components are the movement, case, dial, crystal, crown, and strap or bracelet. Wristwatches serve functions ranging from precise timekeeping to fashion and status symbols, spanning luxury to mass-market segments. Proper care involves regular servicing for mechanical watches, battery replacement for quartz, and checks of seals to maintain water resistance.