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Jaeger-LeCoultre Polaris Perpetual Calendar

Reference Q9088180. A sheet to take with you: the numbers to check the watch against, what to look at, and what to ask. It does not authenticate anything and it does not tell you whether to buy.

Check the numbers

Measure or ask. A watch that does not match these is not necessarily wrong, but it is a question worth the answer.

Anything above marked not recorded is a gap in this catalog, not a property of the watch. Do not read a blank as a zero.

Before anything else

A perpetual calendar inside a sports case, which is an unusual pairing and the reason to be careful: the calendar is the expensive part and the part most likely to have been mishandled by a previous owner.

What to look at

1. dial Calendar alignment when settled
   Correct Day, date, month and year apertures fully framed with no partial characters outside the changeover window
   Red flag An indication sitting between two positions, which suggests a slipped calendar wheel
2. dial Both-hemisphere moon phase
   Correct Both moon apertures track together and agree with the date
   Red flag One aperture static while the other moves
3. crown Upper crown driving the internal bezel
   Correct Turning the upper crown rotates the inner bezel smoothly
   Red flag A bezel that does not respond, or moves on its own
4. movement Cal. 868/AA reserve
   Correct Roughly 70 hours from full wind, seconds hacking on the crown
   Red flag A reserve well short of 70 hours

Known issues on this reference

• A perpetual calendar that has been left to stop must be set forward through every missed day, and forcing the single corrector pusher while the calendar is mid-change is how these get damaged. Ask whether it has ever jammed.
• The moon phase shows both hemispheres. A watch where only one aperture moves is faulty rather than a variant.
• The internal rotating bezel is driven by the upper crown. A bezel that will not turn, or turns without the crown, is a fault.

Parts that are commonly replaced

• Straps and the interchangeable bracelet are swapped routinely.
• Calendar correctors are a service item after mishandling.

Ask the seller, whatever the watch

• When was it last serviced, by whom, and is there paperwork?
• Has the case ever been polished?
• Which parts are not original to it?
• Do you have the box, papers and the original bracelet or strap?
• Why are you selling it?
• Can I see it in daylight, and can I take a photo of the caseback?

What this sheet is standing on

The specifications above are sourced to monochrome-watches.com, fratellowatches.com. What else the catalog does not know.

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