Learn why flight simulator time differs from your PC clock and fix UTC, location, saved-flight, daylight-saving and live-time mismatches.
Your flight simulator time can differ from your computer clock because the simulator runs its own world clock. It may show UTC/Zulu time, local time at the aircraft’s position, a saved scenario’s date and time, or a manually selected setting. Pausing, time acceleration and daylight-saving rules can add further differences.
This behaviour applies broadly to Microsoft Flight Simulator 2020 and 2024, X-Plane, FSX and Prepar3D. A mismatch is normal unless live time is enabled and you are comparing clocks for the same location and time standard.
What does the size of the time difference mean?
The pattern of the mismatch usually identifies its cause.
| Observed difference | Likely cause | What to check |
|---|---|---|
| Several hours but not changing | UTC versus local time, or the aircraft is in another time zone | Aircraft location and whether the display says UTC, Zulu or local |
| Exactly one hour | Daylight-saving time mismatch | Simulator date, PC time zone and automatic daylight-saving settings |
| 30 or 45 minutes | A valid regional time-zone offset | The local time zone at the aircraft’s position |
| The gap grows during the flight | Time acceleration, pausing or loss of live-time synchronisation | Simulation rate, pause mode and live-time setting |
| An old date or time returns after loading | A saved flight, mission or scenario is restoring its own clock | Session settings before starting the flight |
UTC can also be on a different calendar date. For example, late evening in the Americas may already be the following day in Zulu time.
How do I make simulator time match the computer clock?
To match the PC clock, the simulator must use live time while the aircraft is located in the same time zone as the computer.
- Identify which clock is wrong. Compare the simulator’s world or environment time first, not only the clock fitted to the instrument panel.
- Check the aircraft’s location. A flight in Tokyo should show Tokyo local time, even when the computer is set to London time. If you want operational aviation time, compare UTC instead.
- Inspect the simulator date. A custom or historical date changes daylight-saving rules, sunrise and sunset. The simulator date rather than the PC date normally controls these effects.
- Select live or real-world time. Turn off any custom-time option and reload the flight if the change is not applied. Microsoft Flight Simulator users can follow our guide to setting live, custom, local and UTC time.
- Return the simulation rate to normal. Time acceleration deliberately advances the world clock faster than the computer clock. Pause behaviour varies: some pause modes stop the aircraft while time continues, whereas others stop both.
- Verify the PC settings. Check the operating system’s date, time zone, automatic clock synchronisation and daylight-saving option. Correct-looking local time can still be paired with the wrong time-zone setting.
- Check for an enforced session time. Missions, challenges, multiplayer sessions and network hosts may lock the simulator to a preset date or time.
Older simulators can also use time-zone boundaries or daylight-saving data that no longer match real-world rules. For persistent UTC or boundary errors in FSX and Prepar3D, the FS Real Time synchronisation utility is designed to correct simulator time and time-zone behaviour.
Why is only the cockpit clock different?
A cockpit clock may be an independent aircraft instrument rather than a direct display of simulator local time. Airliner clocks commonly use UTC for operations, while some general-aviation clocks must be adjusted manually.
Add-on aircraft may also restore a previously saved panel state. If the sky and simulator interface show the expected time but only the panel clock is wrong, adjust that instrument in the aircraft rather than changing the global simulation time.
Does live weather automatically set live time?
Live weather and live time can be separate settings, so enabling one does not always enable the other. It is possible to use present weather with a custom midday departure, or live time with a weather preset.
METAR timestamps use UTC, which can look several hours different from the PC’s local clock even when both are correct. If clouds, winds or reports appear out of step, check our explanation of live weather and simulator clock synchronisation.
Sunlight is based on the simulator’s date, time and aircraft coordinates. If it is night at your computer’s location but the aircraft is on the other side of the world, daylight in the simulator is expected rather than evidence of a clock fault.