Our own fragile mortality became closely associated with watches as soon as they became even remotely widespread, in the 16th century. One highly predictable effect of developing the technology to measure something is a keener understanding of how much of it you have, after all, and to anyone previously used only to the hourly chimes of a clock, a ticking watch in your pocket could easily come across as a constant, buzzing reminder that time’s-a-wasting.

It wasn’t long before watches whose design actively sought to evoke this awareness became popular. Some had skull-shaped cases or decorations, and many carried the inscription “memento mori”, Latin for “remember you will die”.

Cheerful stuff, when you put it like that. But you have to think about it in context. Across Europe in the 16th to 18th centuries, life expectancy at birth hovered between 30 and 40 years.

This wasn’t the early modern equivalent of “dream as though you’ll live forever; live as if you’ll die tomorrow” typed across an Instagram post of a sunset. The art and literature of the time, not to mention religious texts, focused heavily on mankind’s mortality and the need to be ready for death when it came. This was a reminder to stay humble in the face of death, which for most believers was not just an abstract idea of good behaviour, but something that could have distinct implications for what came next.

Placing pocket-watch movements inside skull-shaped cases might seem impractical, but it was an affectation with serious undertones. In any case, watches were the preserve of the upper classes and not designed for convenient, ergonomic-wear, even in a pocket. They were a statement item, a status symbol to be conspicuously displayed. And there’s not much more conspicuous than a silver skull whose jaw flips up to reveal the time. An ornately engraved example was reportedly given by Mary Queen of Scots to Ms Mary Seaton as the queen travelled to her execution.

Accordingly, the skull-shaped case waned in popularity as pocket watches improved and became more reliable, more necessary for modern life, and more accessible to the middle classes. However, there was a late spike in popularity during the early Victorian era, in line with the popularity of gothic horror motifs in literature and popular culture.

Simultaneously, advances in public health in the 19th and 20th centuries might have changed our relationship with death. In any case, the skulls you see on today’s watches tend to take a stylised form known as the calavera, which will be more familiar to non-Spanish speakers as the kind of skull that features in Mexico’s Dia de los Muertos (Day of the Dead).

These watches, in line with the annual event itself, have the same basic message as their 17th-century forebears, but come at it in a slightly more joyous way. The dead are celebrated; those who have departed are honoured, and we are reminded to make the best of our remaining time.

That’s very much the thinking behind horological designs from the likes of Fiona Krüger and Bell & Ross. Kruger’s designs began as finely decorated watches and have evolved into substantial wall clocks, produced by Swiss specialists L’Épée 1839, and in their colourful embellishments are a direct nod to Day of the Dead celebrations. Bell & Ross meanwhile takes an even more avant-garde approach, modernising the skull to match the geometric lines of the watch case.