Correct the difference in a camera's clock

When you shoot the same moment with different devices, their clocks may not agree. For example, if your phone shows the correct time but your action camera is an hour behind, Merceq sorts footage from the same place as if it were shot at different times.

Merceq finds the clock difference and suggests a correction. With cameras that record satellite (GPS) time, such as GoPro, it compares that time or videos shot with a phone on the same day. The suggestion appears in the camera window and in the notification after import. Merceq doesn’t apply the correction by itself; you need to click once to apply it. When you do, footage from that camera is placed in the correct time order; you can undo it if you like.

Merceq needs enough evidence to make a suggestion: the camera’s satellite time or at least three matching phone clips. Cameras that don’t record satellite time (such as Sony) can only match against phone clips. If there’s not enough evidence, no suggestion appears; enter the difference once yourself, and the correction is applied to all clips from that camera.

Enter a clock difference yourself

You can find Camera clocks in the Camera names window. Cameras with a known shoot time are listed here; cameras with the same name appear in one row. The row shows the clip count and clock correction status, for example “N clips · clock is correct” or “clock was 1 h ahead, corrected”.

1. Open camera settings from Settings → Playback → Camera names → Edit….
2. Find the camera you want to correct in Camera clocks.
3. Click Correct.
4. Enter the time difference in the day / hr / min / sec fields.
5. Choose whether the camera’s clock was ahead or behind while shooting.
6. Click Save. Choose Cancel if you change your mind.
7. After the “N clips changed time” message, sort your clips by date and check them.

Situation when shooting	Difference to enter	Direction to choose
Actually shot at 14:00, camera recorded 15:00.	1 hour	ahead
Actually shot at 14:00, camera recorded 13:00.	1 hour	behind

Choose the direction based on how wrong the camera’s clock was while shooting, not what you need to do to correct the time.

You can enter up to 7300 in the day field, 23 in hours, and 59 in minutes and seconds. Save can’t be used when the difference is zero. You can’t save a clock correction during import; wait for it to finish.

Careful: This correction is applied to all clips from the camera, not just one video. It also applies to clips you import from the same camera later. The date inside the source video isn’t changed; only the shoot time and order used by Merceq are updated. This operation can’t be undone with ⌘Z.