Date windows are these little apertures on a watch's dial (mostly) located at 3o'clock. If you ask some watch enthusiasts about the topic you'll get widely varied opinions... Some people find them useful, others feel that any date aperture ruins the integrity of the dial. But pros and cons aside this little wrist-calendar is extremely popular. Yet it is hard to tell when this trend started... until now.

February 15, 2023

A Brief History of Date Windows

Marcus Siems @siemswatches
Collector, Author, Data Analyst

Heureka! Sometimes I go through some numbers, or am working on my database and new insights hits me. It's been like that with todays topic. Date windows are a topic that splits the watch community in half - some like them, some hate them. Yet it's hard to find any information about this complication and its historical popularity when you search for it. When did people start to fall for these little apertures? And the interesting fact is: There indeed seems to be a distinct point in time when this particular complication became famous.

Date windows are these little apertures on a watch's dial (mostly) located at 3o'clock. Most people will know the Rolex Datejust, a watch that integrated this complication in 1945 for the brand's 40th anniversary and kept the date-wheels turning ever since^[1]. However, the first serially produced watch with a date window already came in 1915 from Movado^[2]. And it took another 15 years until in 1930 a Swiss watch company called Mimo actually introduced the date-window at 3o'clock, the position we most associate with this complication^[3].

vintage 1970s Rolex Oyster Perpetual Date Well... it is not just Rolex's Datejust that made date-window. The Oyster Perpetual Date plays in the same league and strikes many of the same chords as it's larger brother. Photo @goldammer.me.

If you ask some watch enthusiasts about the topic you'll get widely varied opinions... Some people find them useful, others feel that any date aperture ruins the integrity of the dial and should become forbidden. The design aficionados have their point but apparently this little wrist-calendar is very popular. Just looking into the historic prices of steel Rolex Submariners - comparing no-date and date variations - we can observe that hefty premiums came with a date. Between 1957-2023 the "date premium" was on average over 30% and still to this day is at around 12%^[4].

historic retail prices for the Rolex Submariner with and without date complication Figure 1. Historic Retail Prices for Rolex's Submariner lineup - with (blue) and without (light blue) date complication - between 1957 - 2023^[4].

So this not-so-complicated complication appears to be quite a big deal. It is not simply a random gimmick. But these prices don't really tell us too much about popularity yet... Only because this was indeed seen as a valuable complication by watch brands does not necessarily mean it was also accepted by the broader audience.

So here it becomes a bit tricky... how can you compare the popularity of different watches? It's hard to find production numbers anyway and then you'd need to find acceptable pairs of watches to draw a conclusion... Or we can look beyond watches and go directly to the root of this complication - the movement!

vintage IWC Ingenieur 666AD with white dial One of the most classic automatic watches with a date complication of the 1960s - IWC's Ingenieur 666AD (stands for automatic-date) with cal. 8531 from 1966. Photo @goldammer.me.

We have covered some movement production numbers in the past, showing that automatic Audemars Piguet caliber production during the 1950s to 70s did rise quite dramatically^[5-6]. But if we look closer we can also compare movements that featured a date-window versus movements that didn't. On top, I found similar production numbers for compatible IWC automatic calibers from 1954-76 (the 852x-854x series)^[7].

Automatic movement production during the 1950s, 60s and 70s for Audemars Piguet and IWC Figure 2. Production numbers of compatible automatic movements with (dark) and without (light) date complication for Audemars Piguet (red) and IWC (green) between 1953-1976^[6-7]. * AP calibers 2120/2121 were produced until after 1975 but I only found the numbers for this limited period.

We can clearly see that during the 1950s and 60s most people seemed to prefer "clean" time-only watches. Only in the mid-1960s we see an increase in popularity for movements featuring a date aperture. It goes so far that IWC even produced over 3x more date than no-date automatic movements between 1964-76.

Overall, this shows us that the date-window has been highly valued by both watch manufacturers and customers. The complication's popularity spiked during the 1960s and beyond. In other words, for watches with this little aperture it took approximately 50 years since its introduction to finally overtake their time-only ancestors to become the default dial and movement variation.

wrist shot vintage 1960s Patek Philippe 3445 with date A bestseller and a workhorse of Patek Philippe during the 1960s, 70s & 80s. Photo @goldammer.me.

However, it must be said that this evidence so far is a bit anecdotal. It needs to be shown that other brands followed a similar path. Patek Philippe for example launched their ref. 3445 - their first automatic wristwatch with date window - in 1961 and it stayed a cornerstone of their catalogue into the 1980s^[8-10]. The luxury spots models of the 1970s were also automatic watches with a date complication. So this trend might extrapolate beyond the numbers shown here.

The do-it-all-and-don't-worry-about-it watch was definitely a thing in the 1960s. People would typically own one watch and wear it daily - so an automatic watch was extremely handy and so was the date complication. Yet another open question is whether and when this trend ended. Do we see a decline or is the date-window simply the default dial layout since the 1960s? Well I can't tell you now but I will keep you updated! Until then just enjoy your watch and let your phone tell you the date...