Hi Andy, thanks for your response. I was using UTC+2 as time zone. However, I did not use Configuration App 1.3.6. since it has not been available at the end of April. So I used the old firmware and the previous app to configure those devices. I configured the devices in the office but started them (switching to custom) in the field before mounting the boxes to the tree. The metadata for one of the "youngest" from 20200514 files looks like this: So battery obviously has not been a problem, voltage was quiet high at the last files - and the devices were still recording when we collected them after 2 months. Normally they should have run out of battery with the mentioned settings within that time period. We used SD cards "SanDisk Extreme 32GB". I attached a file from 20200515 - you can here, that the device has been in the office and not in the forest while recording... However, we deployed them on 20200430 and collected them on 20200629. By listening to the youngest files of some devices, it seems like there has been a recording rhythm of 2 hours instead of every half hour - I heard myself phoning first at 4:45 pm and on the next file giving an online lecture at 6:45 pm... But those two files are named like 20200515_203000 and 20200515_210000. I do not have an idea about that shifting of the recording rhythm/clock delay. Maybe my only possibility is to manually check the files for the "dawn chorus" and somehow reconstruct the timing by that or check, whether the rhythm of every 2 hours may fit the bird activity pattern for the whole recording period and then rename the files. Or do you have another idea how to reconstruct the timing? Regards, David
