Miyota · Japan
Miyota 90S5
The 90S5 belongs to Miyota's 9000-series family of premium automatic movements, a platform that launched with the 9015 in 2009 as an alternative to Swiss-made movements. The 90S5 is a display-focused evolution of the established 9015/9039 platform.
Sharing the same 26 mm, 3.90 mm-thin architecture as the 9015 (date) and its no-date sibling the 9039, the 90S5 is purpose-built for open-heart and skeleton dial configurations. Its defining feature is an exposed balance wheel visible from the dial side at roughly the 5 o'clock position, backed by a decorated gilt front plate — unusually refined dial-side finishing for a Japanese movement at this price tier.
Because it pairs the visual appeal of the open-heart display with the reliability of the proven 9000-series platform and drops the date complication that requires a cutout in the dial, the 90S5 is positioned as an open-heart option within Miyota's Premium Automatic range.
Hz
Jewels
Reserve
In catalog
Technical specification
| Manufacturer | Miyota |
| Origin | Japan |
| Type | Automatic |
| Beat rate | 28,800 bph · 4 Hz |
| Jewels | 24 |
| Power reserve | 42 h |
| Diameter | 26 mm |
| Height | 3.9 mm |
| Hacking seconds | Yes |
| Hand-winding | Yes |
| Date | No |
| GMT | No |
| Chronograph | No |
| Accuracy (stated) | -10/+30 s/day |
2 models
Watches with this caliber
FAQ
Is the Miyota 90S5 automatic or manual?
The Miyota 90S5 is an automatic (self-winding) movement: a rotor winds the mainspring from the motion of your wrist, so it needs no battery. It can also be wound by hand via the crown.
What is the power reserve of the Miyota 90S5?
About 42 hours on a full wind — into a second day, so it keeps running overnight off the wrist. Power reserve is how long the Miyota 90S5 keeps running once you stop wearing or winding it.
Does the Miyota 90S5 hack (stop the seconds when you set it)?
Yes. Pulling the crown stops the seconds hand, so the Miyota 90S5 can be set precisely to a reference time before you push the crown back in. Hacking is what lets you sync several watches — or a watch and a phone — to the exact second.
Does the Miyota 90S5 have a date function?
No — the Miyota 90S5 has no date complication, so every watch built on it runs a clean, date-free dial. That suits symmetrical and vintage-style designs, and means one less thing to reset whenever the movement is allowed to stop.
How accurate is the Miyota 90S5?
The Miyota 90S5 is rated at -10/+30 s/day. That is a normal working range for an uncertified mechanical movement; a COSC-certified chronometer is held to a tighter −4/+6 s/day, and a watchmaker can usually regulate one closer. Real-world accuracy still depends on how each watch is regulated, worn, and serviced.
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