Studio Underd0g has reached a clear milestone with its fourth collection. Just over five years after the brand first appeared, it now introduces its first calendar watch. Also, the project marks the first time the independent maker has helped shape a movement and its complications. The 04Series Calendar is a bold step for a company known for its colorful, sometimes playful watches. Sure, those traits still exist and are part of the underlying theme, but there’s change afoot. We’re here for it.

As mentioned, the new 04Series Calendar maintains the playful, approachable character that has defined earlier models. Four colorways are inspired by views from out of an office or work window while waiting for the weekend. We received two but will cover all four. Plus, two case diameters give buyers a choice. Interestingly, the sizes are close, but the difference is significant enough to matter. And while the new movement comes from China, every watch is assembled in the UK at The D0ghouse. There, the Studio Underd0g team regulates and inspects each example before delivery. Shall we begin?

Studio Underdog 04SERIES Calendar Cloud10 on its side, crown up

The Studio Underdog 04Series Calendar

Before we get into the individual models, let’s run down the specifications. Buyers can opt for either a 37mm or 38.5mm stainless steel case. Regardless of the diameter, both measure 13.5mm thick including the front and rear crystals, or 10.5mm without. Interestingly, both have a 44.5mm lug-to-lug, and the lugs fit 20mm straps. Apparently, the idea behind offering two diameters was to please the vintage-loving crowd and modern-watch collectors. While this is a calendar watch, the 5atm water resistance rating renders it useful.

Studio Underdog 04SERIES Calendar Shepherd's Delight flat-lay, head on

A nice British touch is that the leather straps come from The Strap Tailor in Buckinghamshire. There are four leather options — Nail Virginia, Chestnut Hidro Pull-Up, Emerald Virginia, and Cameo Cutter. These 20/16mm straps are each equipped with quick-release spring bars and a stainless steel pin buckle. The non-strap option is a stainless steel mesh bracelet with a simple slide-adjustable folding clasp.

Studio Underdog 04SERIES Calendar case profile, crown side, next to Victorinox knife

The dial and functions

While a moonphase calendar watch is a serious complication, Studio Underd0g hasn’t abandoned its whimsical purpose. This is a pointer-date-style watch, but it arrives with a twist. The individual windows align to a date and show predominantly light-colored portions of the disc underneath. Every five days, two darker colors emerge. It doesn’t take a rocket scientist to realize that these are the weekends. Still, it’s a nice visual reminder of when work ends and fun begins.

Studio Underdog 04SERIES Calendar Shepherds Delight dial macro

This underlying wheel can be adjusted via the crown. The pointer date has a retrograde feature and never blocks the moonphase. It is adjustable via a small pusher at two o’clock.

Studio Underdog 04SERIES Calendar Cloud10 on its side, crown up

Four dial options — starting with the Cloud10

The Cloud10 is the first of two pieces we received. Ours happened to come in at 37mm. With its circular-brushed, silvery light blue dial, it presents an airy visage evoking a clear sky. It blends red, pink, and even orange nicely without overwhelming the underlying dial. In a way, it reminds me a little of the Omega Semaster Soccer Timer! Black printing marks the scales, and beveled leaf-shaped silver timekeeping hands join a simple arrow-tipped date pointer. This is all set against a vertically brushed steel case with a matching (non-ridged) coin-like bezel. However, the bezel stops just short of going “full coin” with its slight bevel on the leading edge.

Studio Underdog 04SERIES Calendar mesh bracelet

This piece came with the mesh bracelet, which gave it more of a vintage feel. Frankly, it would work brilliantly on a wide array of strap colors too.

Studio Underdog 04SERIES Calendar Shepherd's Delight pocket shot

The Shepherd’s Delight — a sea of red

The Shepherd’s Delight came to us in the larger 38.5mm 04 Series Calendar size. It’s a subtle visual difference, but the watch has a thicker bezel and shorter-appearing lugs. This dial looks much warmer, representing late-afternoon light (yes, the types of days many of us are experiencing right now). The peripheral weekend windows are still easy to read, though, due to precise CNC-machined day windows. This watch adds light blue and navy to the mix for contrast. We had this on one of the Strap Tailor straps, which looked fantastic. Whereas the Cloud10 felt more dressy, the Shepherd’s Delight is perfect for the outdoors on an Autumn or Winter day.

Studio Underdog 04SERIES Calendar wrist shot 2

What’s the deal with 1.5mm?

Now, before we get to the two dials we did not receive at our headquarters, let’s talk about the petite 1.5mm elephant in the room. On paper, the difference is minuscule, but the reality is that it’s the perfect level of separation between two models. Because of the identical lug-to-lug, it means that only the central portion of the watch is larger. There is a noticeable difference, but not so much that one would look gigantic or the other too petite.

The Arabian Sky and the 0vercast

While our focus has been on the 04Series Calendar models we were fortunate to go hands-on with, we can’t omit the final two references. The Arabian Sky model has a dial similar to the midnight blue on tuxedos. Here, though, the blue tone is preserved under the double-domed sapphire dial. A rather unconventional, but seriously cool, blend of orange, yellow, and cream comes together to create the model with the most contrast. It’s a tough call, but I think this model just might edge out the Cloud10 as my favorite! The 0vercast brings a bronzy salmon dial in what might be the most formal-looking edition. On this model, turquoise, aqua, and white square off against the competing dial and silvery hands to great effect. Without a doubt, the polished inner moonphase subdial ring is the most prominent on this piece.

Studio Underd0g 04Series Calendar case back and movement

A new automatic created with Seagull

Studio Underd0g partnered with Seagull to create a dedicated automatic caliber (the brand’s first automatic) for the 04Series Calendar. This took more than two years, and ultimately required 34 new components. The Seagull ST-2115B emerges with a frequency of 28,800vph (4 Hz), has 42 hours of power reserve, and includes hacking. Expect an accuracy of +15/-10 seconds per day. As an added touch, the rotor shows off the exclusive partnership between the two. All of this is on view via the sapphire display and screw-down case back.

Studio Underdog 04SERIES Calendar Cloud10 flat-lay, head on

Final thoughts on the 04Series Calendar

The 04Series Calendar will be available starting November 17th through Studio Underd0g’s website and by appointment at The D0ghouse in Maidenhead, England. Suggested retail prices start at £750 / US$1,100 / €800 / CHF 800 / C$1,300 / A$1,400 / AED 3,500, with free worldwide shipping. A limited two-year warranty covers each watch. In short, the 04Series Calendar gives Studio Underd0g its first automatic movement, a unique take on calendar complications that prioritize the weekend, and four dial colors across two case sizes. Collectors who value independent character and practical functions will find the series a lively addition to the brand’s growing line.

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Watch specifications

Model
04 Series Calendar
Reference
04CLCH (Cloud10), 04ASEM (Arabian Sky), 04SDNA (Shepherd's Delight), 04OVCA (0vercast)
Dial
Light blue (Cloud10), Dark blue (Arabian Sky), Red (Shepher's Delight), Bronze salmon (0vercast)
Case Material
316L stainless steel
Case Dimensions
37mm/38.5mm (diameter) × 44.5mm (lug-to-lug) × 13.5mm (thickness with crystals, 10.5mm without)
Crystal
Double domed sapphire
Case Back
Stainless steel with sapphire display, screw-in
Movement
Seagull ST-2115B for Studio Underd0g: automatic with manual winding and hacking seconds, 28,800vph (4Hz) frequency, 42-hour power reserve, accuracy of -10/+15 seconds per day
Water Resistance
5 ATM (50 meters)
Strap
Stainless steel mesh bracelet (20mm) or leather strap by The Strap Tailor (20mm/16mm) with stainless steel pin buckle
Functions
Time (hours, minutes), retrograde pointer date, weekend indicator, moonphase display
Price
€800 / £750 / $1,100 / CHF 800 (including worldwide shipping)
Warranty
Two years