I've noticed a strange phenomenon when recording video. The timestamp is different on the cache file on my phone versus the file recorded on the sdcard.
For example, On the sdcard I see recorded file DJI_0054.MP4 modified 9/19/20 5:17PM
But my phone has a file 2020_09_19_16_13_11_Cache.mp4 which shows modified 9/19/20 4:17PM
The filename of the cache file indicates 16_13 which was the start time of the recording.
So why does the sdcard recording show an incorrect time? Does the mini set the timestamp or the phone? Maybe they handle daylight savings time differently?

I don't remember the details, but it has been observed and discussed before.  Yep it does.  I seem to recall that it related to Daylight Savings Time.  W'll see after this weekend.

Hello there Wysocki. I am sorry for the trouble this has caused and thank you for reaching out. Kindly please make sure to adjust your time settings on your mobile device in a correct date and time to see if the issue will persist. May we also know what is the model and specifications of the SD Card you are using please? Thank you.

The sdcard is a SanDisk 64GB Extreme microSDXC UHS-I. Not sure how that would make a difference though. The phone is a Samsung Galaxy S10 and it's set to Automatic date & time provided by my network (Verizon).

But the incorrect time on the sdcard is neither daylight savings time nor standard time. The cache file show the correct Daylight time of 4:17PM. If the file on the sdcard was showing Standard time, that would be 3:17PM, not 5:17. It really will be interesting to see what happens this coming sunday. I can't imagine that the mini has its own clock onboard. If it does, what is it syncing with?

Does anyone else experience this issue? Just shoot a quick video and compare the sdcard file time with the cache file time on the phone.

Same here on a DJI Mavic 2 Pro and it has nothing to do with SD card, type of Phone or Phone time settings (I used multiple SD card from different brands and 3 different iPhones all set to the timezone of the country I was in). I travelled in 3 different countries with different timezone and the timestamp is always correct on the photos but never on the videos. First, when I moved from France to New Zealand, the timestamp of videos was ahead of 12h (the timezone difference between the 2 countries). Then, we changed hour in New Zealand and the timestamp of videos offset by 11h (the new timezone difference between the 2 countries). I then moved to Samoa and the timestamp of videos was ahead by only one hour now (the timezone difference between New Zealand and Samoa).

It's been a recurrent issue noticed by many DJI drone users that doesn't seem to be solve by DJI. I hope my comment will help you solve this problem as it seems to be a complex one depending on the previous country you visited, the new you are in and the timezone difference between them. However, I still don't understand how the software can timestamp photos correctly but not the videos?!

Well, the problem seems to be related to daylight savings time as my drone has never traveled out of this time zone. We just went into Pacific Standard Time. I did a test video and the file timestamp on the sdcard IS correct. It is evidently taken from the network time of my phone. The problem is that the phone already considers DST and so DJI should just use that for the timestamp. Instead it decided to "fix" the time by adding an hour, which should have actually been subtracted to get to standard time. In any case, it's wrong, it's a bug, and it needs to be corrected for the sake of anyone trying to put together a bunch of clips in post processing and not having a clue where they fit on a timeline. (While I'm ranting, why can't DJI put the timestamp into the fileNAME like the cache file does? That would also make life easier!).

Hopefully someone at DJI is reading this and can actually do something before DST starts again on March 14, 2021. We'll see then.

Could it be something to do with one using GPS time and the other local time? I recollect something similar with a DLSR that had GPS and reported GPS and local times that differed by 1 hour

Well, here it is, 3/14/21 and daylight saving time has begun. I ran a test last night on the mini and the sdcard recorded a scene and properly timestamped it with pacific standard time. This morning I ran another test shot and the cache file on my phone was timestamped correctly in DST. HOWEVER, the mp4 file on the sdcard was stamped an hour LATER than even the new DST time!

To clarify, when I took the shot, standard time was 10:30am but the current DST was 11:30am, but the mini recorded the scene as 12:30pm -  a time which is in the future even as I post this!!! It appears as though there's code in the bird that says "I'm about to record a file and it's now DST, so I better add an hour to whatever time the phone just sent me" - as if the phone wasn't already adding the hour. I can't believe DJI would have allowed such sloppy code in their product for so long. This will be my first and last DJI purchase.