Citizen Tsuki-yomi A-T BY1010-57X
Ref. BY1010-57X · Green dial · In production
- Case43 mm
- Water res.100 m
- MovementSolar
- CrystalSapphire
Citizen Tsuki-yomi A-T BY1010-57X size, specs and price at a glance
The Citizen Tsuki-yomi A-T BY1010-57X is 43 mm wide. Citizen does not publish its lug-to-lug length. It takes 22 mm straps and ships on a bracelet. Inside is the H874 solar calibre, water resistant to 100 m. US list price: $895 when we last checked citizenwatch.com (3 Nov 2026).
Strap shopping? See our Citizen lug width chart.
Overview
The Citizen BY1010-57X is a gmt watch from the Tsuki-yomi A-T collection. It has a 43 mm titanium case. Citizen lists the dial as green. Inside is a solar movement (calibre H874). You also get 100 m water resistance, a sapphire crystal and a bracelet.
Who it suits
- Wrists of roughly 17.2–19.1 cm (6.8–7.5 in), by our Watch Finder sizing guide
- Everyday wear including swimming
- Frequent travellers who track two time zones
- Grab-and-go wear without winding or setting
Strengths
- Sapphire crystal resists scratches
Written by Watch.co from the published specs below. These are not owner reviews.
Full specifications
Case
| Case diameter | 43 mm | citizenwatch.com · 3 Nov 2026 |
|---|---|---|
| Lug-to-lug | Not published by Citizen | |
| Case material | Titanium | citizenwatch.com · 3 Nov 2026 |
| Crystal | Sapphire | citizenwatch.com · 3 Nov 2026 |
| Water resistance | 100 m | citizenwatch.com · 3 Nov 2026 |
Dial
| Dial colour | Green | citizenwatch.com · 3 Nov 2026 |
|---|---|---|
| Date | Day/Date | citizenwatch.com · 3 Nov 2026 |
| GMT / second time zone | Yes | citizenwatch.com · 3 Nov 2026 |
| Moon phase | Yes | citizenwatch.com · 3 Nov 2026 |
Movement
| Movement type | Solar | citizenwatch.com · 3 Nov 2026 |
|---|---|---|
| Calibre | H874 | citizenwatch.com · 3 Nov 2026 |
Strap / Bracelet
| Bracelet / strap | Bracelet | citizenwatch.com · 3 Nov 2026 |
|---|---|---|
| Lug width | 22 mm | citizenwatch.com · 3 Nov 2026 |
Other
| US list price (MSRP) | $895 | citizenwatch.com · 3 Nov 2026 |
|---|---|---|
| Production status | In production | citizenwatch.com · 3 Nov 2026 |
| Style (our classification) | GMT | our classification |
Specs are summarised in our own words from the brand's product page. Each row links its source and the date we checked it. Fields we haven't verified are left out rather than guessed.
Variants with the same specs
Same case, movement and bracelet or strap; typically a different dial or finish.
Similar alternatives
Picked with Watch Finder's style tags and sizing.
Questions about the Citizen Tsuki-yomi A-T BY1010-57X
How big is the Citizen Tsuki-yomi A-T BY1010-57X?
The case is 43 mm wide.
What movement does the Citizen Tsuki-yomi A-T BY1010-57X use?
It uses the H874 calibre, a solar movement.
Can I swim with the Citizen Tsuki-yomi A-T BY1010-57X?
Yes. It is rated to 100 m.
Does the Citizen Tsuki-yomi A-T BY1010-57X have a date?
Yes, it shows the day and date.
How much is the Citizen Tsuki-yomi A-T BY1010-57X?
The US list price was $895 on citizenwatch.com when we checked on 3 Nov 2026. Prices change, so check before you buy.
Will the Citizen Tsuki-yomi A-T BY1010-57X fit my wrist?
By our sizing guide it sits best on wrists of about 17.2–19.1 cm (6.8–7.5 in). Use the fit checker on this page to test your own wrist.
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