Rolex · Rolex 3285

Rolex GMT-Master II and Explorer II power reserve: inside the calibre 3285

The calibre 3285 powers every current Rolex GMT-Master II, from the Pepsi and Batman to the Sprite, and the Explorer II. From full it runs for about 70 hours, just under three days.

Updated September 2026 · Based on manufacturer specs, published reviews and watchmaker/owner reports

Watches that use the Rolex 3285

The 3285 is Rolex's GMT movement: a date, a 24-hour hand for a second time zone, and a local hour hand you can jump forward or back an hour at a time. Rolex introduced it in 2018 in the GMT-Master II, and moved the Explorer II onto it in 2021. It isn't used outside Rolex.

Its siblings are the 3235 (date only, as in the Submariner Date and Datejust), the 3230 (no date) and the 3255 (day and date).

Specs at a glance

History and where it came from

Rolex's GMT-Master II has had a jumping local hour hand since the calibre 3085 of the early 1980s. The idea is simple: when you land somewhere new, you move only the hour hand, an hour at a time, while the minutes, seconds and 24-hour home-time hand keep running. The date follows the local hour hand, forwards or backwards.

The 3186, used in the GMT-Master II through the 2010s, did all of that with about 48 hours of reserve. At Baselworld 2018, Rolex launched the steel "Pepsi" on a Jubilee bracelet with a new movement: the 3285. It was the only new Rolex calibre that year, and it brought the GMT onto the same 32-series architecture as the Day-Date's 3255 and the Datejust's 3235, with the Chronergy escapement and a thinner-walled barrel holding a longer mainspring. Reserve went from 48 hours to 70.

The "Batman" moved to the 3285 in 2019, and when Rolex updated the Explorer II in 2021 it replaced the 3187 with the same movement. On the Explorer II, the 24-hour hand is paired with a fixed 24-hour bezel instead of a rotating one, but the mechanism underneath is the same.

Accuracy in the real world

Like every modern Rolex, each 3285 watch is COSC-certified as a movement and then tested by Rolex after casing to -2/+2 seconds a day. Owners of the GMT-Master II and Explorer II generally report new watches inside that range, often a second or so fast. Because the test is on the finished watch, it's a better guide to what you'll see on the wrist than a bare-movement certificate.

The 3285 is part of the 32-series family, and owners and watchmakers have reported that some early 32-series watches began running slow after two or three years, usually put down to lubrication and low amplitude. Rolex hasn't said anything publicly, but affected watches have reportedly been fixed under the five-year guarantee. If a GMT that used to keep good time starts losing several seconds a day, take it back while it's covered.

Using the GMT function doesn't affect timekeeping. Jumping the local hour hand doesn't stop the balance, so you can change time zones on a plane without losing a second.

Reliability and servicing

Rolex recommends a service roughly every ten years for watches sold since 2015, and gives a five-year guarantee.

• Brand service. Rolex service centres have full parts access and replace the barrel and mainspring together when needed.
• Independents. The 32-series design makes some jobs harder than on the 3186: watchmakers point to the thin barrel wall that isn't meant to be reopened, the sealed ball-bearing rotor assembly, and parts restricted to Rolex's own network.
• More moving parts. The GMT works add a jumping hour mechanism and a second hand stack on top of the date. They're robust, but they're one more thing to treat gently. Don't force the hour hand if it resists.

Quirks worth knowing

• No separate date quickset. You set the date by jumping the local hour hand past midnight, forwards or backwards. It's quick once you're used to it, but it surprises people coming from a Submariner Date.
• Setting from stopped. Pull to the last position to set the 24-hour hand and minutes (this stops the seconds hand), then push in one position and jump the local hour hand to the right hour and date.
• Unscrew first. The Triplock crown screws down. Unscrew it before winding and screw it down firmly afterwards.
• Left-handed Sprite. On the 126720VTNR the crown is at 9 o'clock and the date at 9, but the movement and setting sequence are the same.

How it compares

• Rolex 3235: the date-only sibling in the Submariner Date and Datejust. Same reserve, accuracy standard and escapement.
• Rolex 3135: the older date movement from the same era as the 3186. Around 48 hours, and simpler for independents to repair.
• Tudor MT5652: Tudor's in-house GMT for the Black Bay GMT, also with a jumping local hour hand and a 70-hour reserve, under COSC rather than Rolex's cased test.
• Omega 8900: the Aqua Terra and Planet Ocean movement. Omega's GMT versions share its architecture: Master Chronometer 0/+5 s/day, about 60 hours of reserve.

Living with the 70-hour reserve

A fully wound GMT-Master II taken off at 6pm on Friday should still be running around 4pm on Monday. That matters more for a GMT than most watches: if it stops, you have to reset the home time, local time and date, not just the minutes.

It also matters when you travel. The Pepsi that sat in the safe for a four-day trip while you wore something lighter will have stopped. A fully wound one left on the dresser over a normal weekend won't, but one that went into the weekend after a desk day may not make it to Monday. Watch Winder counts down this 70-hour reserve for each watch you own and reminds you before it stops, so the Explorer II is still running and still set when you reach for it. To check a particular weekend, try the "Will my watch stop?" calculator.

Verdict

The 3285 is one of the most useful movements Rolex makes. It has a genuinely practical travel GMT, a 70-hour reserve that covers a weekend, magnetism-resistant parts and a -2/+2 s/day cased standard. In a GMT-Master II or Explorer II it's a watch you can set once for a trip and forget. The caveats are the 32-series ones: some early examples have developed slow-running problems, and independents have fewer repair options than with the 3186. Keep the warranty card, and let Rolex do the service.

FAQ

How long does a Rolex GMT-Master II run off the wrist?

Current GMT-Master II models use the calibre 3285 and run for about 70 hours from full, just under three days. GMT-Master IIs made before 2018, and the Batman before 2019, used the 3186 with about 48 hours.

How accurate is the Rolex GMT-Master II Pepsi?

Rolex tests every cased GMT-Master II to -2/+2 seconds a day as a Superlative Chronometer. Most owners report new watches running within that range.

Does the Rolex GMT-Master II hack?

Yes. Pulling the crown out to its last position stops the seconds hand so you can set the minutes precisely.

How do you change the date on a GMT-Master II?

Pull the crown to the first setting position and jump the local hour hand past midnight, forwards or backwards. There's no separate date quickset on the 3285.

What is the power reserve of the Rolex Explorer II 226570?

About 70 hours. The 226570 uses the same calibre 3285 as the GMT-Master II, up from about 48 hours in the previous 216570.

Will my Rolex Batman stop over the weekend?

Not if it was fully wound. A 126710BLNR runs about 70 hours from full, enough for Friday evening to Monday afternoon, but one that started the weekend half-wound can stop on Sunday.

Does the GMT-Master II Sprite use a different movement?

No. The left-handed 126720VTNR uses the same calibre 3285, with the crown and date moved to the left side of the case.

Sources

• Monochrome: Rolex GMT-Master II Pepsi 126710BLRO with calibre 3285
• Monochrome: Introducing the Rolex Explorer II ref. 226570
• Wikipedia: Rolex GMT Master II
• Quill & Pad: A watchmaker's comparison of Rolex calibres 3135 and 3235

Keeping it running

• On an average day an automatic gains roughly 4 hours of reserve per hour on the wrist, so about 18 hours of wear fills the Rolex 3285. Desk days charge more slowly.
• Most automatics can also be wound by the crown. If yours has stopped, a few dozen turns gets it going before you put it on.
• Off the wrist it stops about 70 hours after it was last full. Stopped sooner?
• On a watch winder, start at about 650 turns per day, both directions. Winder settings for every movement.
• If it does stop, don't set the date between 9pm and 3am. Check if it's safe.

All Rolex movements · Other 70-hour movements

Never let it stop

Watch Winder counts down the reserve of every watch you own and reminds you before one stops. It already knows the Rolex 3285: type your watch's name and the reserve fills itself in.

Manufacturer's published figure. Real reserve varies with the watch's age and service; check your manual.