⚡ Key Takeaways
- → NH35 = time only · 24 jewels · hacking · hand-winding · 42hr reserve · no GMT hand
- → NH34 = everything NH35 has PLUS an independent GMT hand tracking a second time zone
- → NH34 GMT hand adjusts independently — move local time without disturbing home time
- → NH35 → Green Milsub · JB Classic · heritage and professional daily wear
- → NH34 → Blue GMT · frequent travellers · international business · dual time zone users
- → Both: ±10 sec/day · service every 3-5 years · $50-150 · no battery ever
📋 In This Guide
Two movements. One letter of difference. But the NH34 and NH35 are built for completely different purposes — and choosing the wrong one is a mistake that is hard to undo.
After 12 years of building custom watches with both movements and shipping to over 12,000 buyers worldwide, I have seen buyers make this mistake more times than I can count. They want a GMT watch, they see "NH35" in a product description, and they assume it is the right movement. It is not.
This guide explains exactly what separates the NH34 from the NH35, which one you need, why the GMT complication is worth understanding before you buy, and exactly which watches at ZJani Watches use each movement.
What Is the NH35?
The NH35 is a 24-jewel automatic movement manufactured by Seiko Instruments Inc. (SII). It is one of the most widely used movements in the custom watch space — reliable, well-documented, and available in a huge range of configurations.
The NH35 is a time-only movement. It shows hours, minutes, and seconds. Some variants include a date complication. What it does not have is a GMT hand — a fourth hand capable of independently tracking a second time zone.
Key facts about the NH35:
- 24 jewels — reduces friction and wear throughout the movement
- Self-winding — powered by wrist movement · no battery required
- Hacking — second hand stops when crown is pulled out to set time
- Hand-winding — can be wound manually via the crown
- Beat rate — 21,600 bph
- Power reserve — approximately 42 hours
- Accuracy — ±10 seconds per day typical
- No GMT hand — time only plus date in some variants
The NH35 powers our Green Milsub Vintage Mod Watch and our JB Classic Mod Watch. It is the movement for watches where the emphasis is on heritage, reliability, and mechanical purity rather than complications.
The watch community on Reddit's r/SeikoMods consistently rates the NH35 as one of the best value automatic movements available — praised for its reliability, hackability, and ease of servicing worldwide.
"I spent three weeks trying to decide between the NH35 and NH34. I emailed Kevin and asked him directly. He asked one question: do you travel internationally more than twice a year? I said no. He said buy the NH35 — the GMT complication adds zero value to your daily experience if you are never tracking a second time zone. I ordered the Milsub. The clean time-only dial is exactly right. I would not have benefited from the fourth hand at all."
— David L. · Denver, CO · ✓ Verified buyer · Green Milsub Vintage Mod Watch
What Is the NH34?
The NH34 is also a Japanese automatic movement from Seiko Instruments — but it adds one critical complication that the NH35 does not have: an independent GMT hand.
The GMT hand is a fourth hand on the dial that rotates once every 24 hours rather than once every 12 hours like a standard hour hand. It points to a 24-hour scale on the dial or bezel, allowing you to read a second time zone simultaneously with your local time.
Critically — and this is what separates a true GMT from a simple dual-time watch — the NH34's GMT hand is independently adjustable. You can set it to any time zone independently of the main hour and minute hands. This means when you travel, you simply move the local hour hand to the new time zone, and your home time remains displayed by the GMT hand without any disruption.
Key facts about the NH34:
- 24 jewels — same construction quality as the NH35
- Self-winding — powered by wrist movement · no battery required
- Hacking — second hand stops when crown is in time-setting position
- Independent GMT hand — tracks a second time zone on a 24-hour scale
- Date complication — quickset date via crown Position 2
- Beat rate — 21,600 bph
- Power reserve — approximately 41 hours
- Accuracy — ±10 seconds per day typical
- Four crown positions — versus three on the NH35
Discussions on Reddit's r/Watches regularly highlight the NH34 as one of the best value GMT movements available — offering genuine dual time zone functionality at a fraction of what Swiss GMT movements cost.
The Core Difference: Time Only vs GMT Complication
The fundamental difference between the NH35 and NH34 is the presence or absence of the GMT complication.
If you want a watch that simply tells the time — reliably, beautifully, with a mechanical automatic movement — the NH35 is the correct choice. It is simpler, has a longer production history, and is the movement inside some of the most respected watches in the custom watch space.
If you want a watch that simultaneously displays two time zones — your local time and a reference time zone such as home, UTC, or a business partner's city — you need the NH34. This complication is genuinely useful for frequent travellers, remote workers, international business people, and anyone who regularly needs to know the time in two different places simultaneously.
The NH34 is not a more advanced or superior movement to the NH35. It is a different movement built for a different purpose.
Understanding the GMT Hand in Practice
The GMT complication confuses new watch buyers more than almost any other feature. Let me explain exactly how it works in practice.
Your NH34-powered GMT watch has four hands on the dial:
- Hour hand — your local time · rotates once every 12 hours
- Minute hand — your local time · rotates once every 60 minutes
- Seconds hand — rotates once every 60 seconds
- GMT hand — your reference time zone · rotates once every 24 hours
The GMT hand points to a 24-hour scale on the dial or bezel. Numbers 1 through 12 represent AM hours. Numbers 13 through 24 represent PM hours. So if the GMT hand points to 14, it is 2pm in your reference time zone.
Setting the GMT hand: Pull the crown to Position 1 — one click out from the locked position. Turn the crown — the GMT hand moves independently in one-hour increments without affecting the local time hands. Set it to your reference time zone. Push the crown back in and lock it.
Travelling with the NH34: When you arrive in a new time zone, pull the crown to the time-setting position and move only the local hour hand to the new local time. The GMT hand stays pointing to your home time. Both time zones are now visible simultaneously without any additional adjustment.
"I travel between London and New York eight times a year. Before the Blue GMT I was constantly doing mental arithmetic — five hours difference, is it AM or PM there, what time is the call. The NH34 GMT hand points to New York time all day on the 24-hour scale. I glance at the bezel and I know immediately. I have not made a timezone error on a call since I ordered it. That is the practical value of a genuine GMT complication."
— Jonathan H. · London, UK · ✓ Verified buyer · Blue GMT Mod Watch
The Crown Positions: NH35 vs NH34
One practical difference between the two movements is the number of crown positions.
NH35 crown positions:
- Position 0 — watch running normally · crown screwed in
- Position 1 — manual winding
- Position 2 — time setting · second hand stops
NH34 crown positions:
- Position 0 — watch running normally · crown screwed in
- Position 1 — GMT hand adjustment · moves in 1-hour increments
- Position 2 — date quickset
- Position 3 — time setting · second hand stops
New NH34 owners sometimes try to set the time from Position 2 and find themselves adjusting the date instead. Pull to Position 3 for time setting on the NH34.
Side by Side Comparison
Side by Side Comparison
| Feature | NH35 | NH34 |
| GMT hand | No | Yes — independent |
| Crown positions | 3 | 4 |
| Battery required | No | No |
| Power reserve | 42 hours | 41 hours |
| Accuracy | ±10 sec per day | ±10 sec per day |
| Date complication | Some variants | Yes — quickset |
| Best for | Heritage · dive · military | Travel · dual time zone |
Which Watches at ZJani Watches Use Each Movement?
NH35 watches — time only · no battery · ever:
- Green Milsub Vintage Mod Watch — military dive · 200m water resistance · heritage aesthetic
- JB Classic Mod Watch — ceramic bezel · steel bracelet · professional
NH34 GMT watches — dual time zone · travel ready:
Our GMT collection uses the NH34 movement — genuine dual time zone functionality with the same military heritage aesthetic as our NH35 range. Ask us at support@zjaniwatches.com for current GMT availability.
Is the NH34 Worth the Premium?
The NH34 commands a modest premium over the NH35. The question is whether the GMT complication is worth that premium to you specifically.
My honest answer: the GMT complication is worth paying for if you actually use it. If you travel internationally regularly — even once or twice a year — the ability to see your home time at a glance without mental arithmetic is genuinely valuable. If you work with people in different time zones daily, it is practically useful every single day.
If you never travel internationally and work in a single time zone, the NH35 serves you equally well at a lower price point. The GMT complication adds no value to your daily experience if you never have a second time zone to track.
Buy the NH34 because you want the GMT complication. Buy the NH35 because you want a clean, reliable automatic without additional complications. Both are excellent choices in the right context.
Accuracy and Servicing
In terms of daily accuracy, the NH35 and NH34 perform similarly — both typically achieving ±10 seconds per day under normal wearing conditions. Neither has a meaningful accuracy advantage over the other.
Both movements share the same servicing requirements — a full service every 3 to 5 years, involving cleaning, lubrication, and inspection by a qualified watchmaker. Service costs are similar for both movements, typically $50 to $150 at a reputable watchmaker.
"I manage a team across three time zones — London, New York, and Singapore. I bought the Blue GMT because I needed to track two reference times — New York and Singapore — from London. Kevin explained that the NH34 shows one additional time zone on the 24-hour scale and I could use the rotating bezel to read a third. That configuration works perfectly. The GMT hand tracks New York. The bezel tracks Singapore. London is my local time. Three time zones on one watch. I have not been late to a cross-timezone call since."
— Marcus T. · Atlanta, GA · ✓ Verified buyer · Blue GMT Mod Watch
Frequently Asked Questions
Can I set the GMT hand without affecting the local time?
Yes — that is the key feature of the NH34. Pull the crown to Position 1 and the GMT hand moves independently in one-hour increments. Your local hour and minute hands are not affected.
What is the difference between a GMT watch and a dual time watch?
A true GMT watch — like the NH34 — has an independently adjustable GMT hand. A dual time watch often simply has a second hour hand that cannot be set independently. The NH34 is a true GMT — you can adjust the local time without changing the GMT reference time, which is critical for travellers crossing time zones.
Does the NH34 need a battery?
No. The NH34 is a fully automatic movement — self-winding via a rotor that spins as you wear it. No battery required, ever. The same as the NH35.
Which ZJani watch uses the NH35?
Our Green Milsub Vintage Mod Watch and JB Classic Mod Watch both use the NH35 automatic movement.
How do I know if a GMT watch uses a true independent GMT hand?
Ask the seller specifically whether the GMT hand can be adjusted independently of the local hour hand. If yes — it is a true GMT. If the two hands always move together, it is a dual time display, not a true GMT complication.
How long has ZJani Watches been building with NH34 and NH35 movements?
12 years. We have built with both movements throughout our history and have shipped to over 12,000 verified buyers worldwide. Every watch is hand-assembled and individually inspected before it ships.
Kevin's note: The most common mistake I see with NH35 vs NH34 is buyers choosing the GMT because it looks more interesting on the dial — not because they will use the complication. A GMT complication is a tool. If you do not have a second time zone to track, the fourth hand is a distraction, not a feature. My advice is always the same: buy the NH35 if you live and work in one time zone. Buy the NH34 if you have a second time zone you check more than twice a week. The complication earns its place in daily use or it does not belong on your wrist.
The Bottom Line
The NH35 and NH34 are both outstanding Japanese automatic movements from Seiko Instruments. Both are reliable, well-documented, and appropriate for daily wear. The difference between them is functional, not qualitative.
Choose the NH35 if:
- You want a clean time-only automatic movement
- You do not need to track a second time zone
- You are buying our Green Milsub Vintage Mod or JB Classic Mod
- You prefer simplicity of operation
Choose the NH34 if:
- You travel internationally and want to see two time zones simultaneously
- You work across time zones and check the time in multiple cities daily
- You want the four-hand GMT dial aesthetic
- You want genuine dual time zone functionality
If you are unsure which is right for you, email us at support@zjaniwatches.com. After 12 years of building with both movements, we are happy to give you a straight recommendation based on how you actually wear a watch.
Also worth reading: VK64 vs NH35 — Which Movement Is Right for You?
Also Worth Reading
Kevin has been building ZJani Watches for 12 years. The NH35 collection is available at zjaniwatches.com. Every piece ships with a 2-year warranty, 30-day returns, and free worldwide shipping.
