How to set up the Omega Speedmaster Moonphase Master Chronometer (calibre 9904)
Short answer: Pull the crown to position 2. Turning forwards moves only the moon and turning backwards moves only the date. Centre the full moon, then add one notch per day since the last full moon. Set the time at position 3.
Speedmaster Moonphase Master Chronometer at a glance
| Reference | 304.33.44.52.03.001 |
|---|---|
| Calibre | 9904, automatic, about 60 hours |
| Crown | Three positions: 1 = winding, 2 = moon (forwards) and date (backwards), 3 = time with stop-seconds |
| Moon | At 6 o'clock. One notch = one day, so count the days since the last full moon. |
| Water resistance | 10 bar (100 m) |
What do you need to set on the Speedmaster Moonphase Master Chronometer?
Set up moon phase on the Omega Speedmaster Moonphase Master Chronometer
N is the number of whole days since the last full moon. The interactive guide works it out for your location and today's date, and shows the exact count.
- 1
Pull to position 2
Turning forwards now moves only the moon disc.
- 2
Turn forwards to FULL moon
Stop when the full moon is centred.
🎯 Full moon centred - 3
Then N more notches
One notch for each day since the last full moon.
- 4
Push the crown in
Back to 1.
Reset chronograph hands on the Omega Speedmaster Moonphase Master Chronometer
- 1
Check: is the chrono stopped?
Top pusher starts and stops. Bottom resets, but only when stopped.
- 2
Still not at zero? Service
On this mechanical movement the hands are reset by internal cams. There's no user re-alignment, so an authorised service centre needs to fix it.
Pressing pushers in other crown positions won't help, and can cause damage.
Set up the date on the Omega Speedmaster Moonphase Master Chronometer
- 1
Pull to position 2
Turning backwards now moves only the date.
- 2
Turn backwards to set the date
Stop on today's date, then push in.
Set the time on the Omega Speedmaster Moonphase Master Chronometer
- 1
Pull to position 3
The seconds hand stops.
- 2
Set the time
Turn either way. Push to 1 on the time signal.
Start a stopped watch on the Omega Speedmaster Moonphase Master Chronometer
- 1
Wake it up
If unworn for 60+ hours, wind with the crown in position 1.
- 2
Pull to position 3
The seconds hand stops.
- 3
Set the time
Turn either way. Push to 1 on the time signal.
What owners run into
- Mixing up directions: forwards is moon, backwards is date. Turning the wrong way changes the other display.
- If you're unsure where the moon is, centre the full moon first. It is the easiest position to judge by eye.
How the Speedmaster Moonphase Master Chronometer differs from similar watches
The only Speedmaster here that sets its moon with the crown. The older 1866 Moonphase uses side correctors and is hand-wound, while the 9904 winds itself.
Quick answers
How do I set the moon on the Speedmaster Moonphase 9904?
Crown to 2, turn forwards to the full moon, then one notch for each day since the last full moon.
How do I change the date on the 9904?
Crown to 2 and turn backwards.