Hello, I was given some AudioMoth files and have a question regarding the time zones. According to the CONFIG file, the time zone of the recordings was UTC, the recording duration 30 min, the recording period 08:30-21:00 UTC, and the firmware version 1.6. The files are also named in this convention, starting with for example ‘20220608_083000.WAV’. All would be fine, but the ‘date modified’ of this example file states that it was modified at ‘2022-06-08 11:59:58 UTC’, which seems to suggest that it was actually recorded at 08:30 local time (which is UTC-3 here) instead of UTC time. So now I’m not sure whether the recordings started at 08:30 UTC or 08:30 UTC-3. Is there any way to figure this out still? Help would be much appreciated!
Kind regards, Yannick
Thank you very much, it's clear to me now!
It is 08:30 UTC.
Be wary of the modified and file creation dates when there is a time zone difference between when the recordings were made and where your computer is now. The FAT32 and exFAT file formats don't encode timezone information (I guess they didn't think they'd need it originally), so your computer will apply some additional time conversion to the raw time it reads from the file allocation table on the SD card. This then no longer corresponds to the original timezone and generates a lot of confusion. Even daylight saving time changes creates problems with these times. The filename will always be in the start time in the timezone set on the device when it was configured (and reported in the CONFIG.TXT file). The WAV file header also reports the full time of when the recording was started along with the time zone offset. You should go by these times.