For the last week or so the date and time in my original AC200 has been accurate even when I turn it off for 12-18 hours at a time. This afternoon when I turned the AC200 on, the date showed 2021-13-01. Yesterday the date was 2020-12-30. When I use the Settings screen and set the date to 2020-12-31 and set the time then press ok. The main screen comes up with the time I set it to but the date is 2021-13-01. When I go back in the date settings screen the date shows 2020-12-31. I No matter what I try it seems that the current firmware does not accept the date as 2020-12-31. It does appear to accept 2021-01-01 and display that date correctly. Is anyone else seeing the incorrect date issue on their AC200? If this is a firmware issue when will Bluetti correct this problem?
Why do we need to have the date?
When would you need to use that feature?
Just curious.
It appears that the date and time are used when recording/logging fault history. If that is all it is used for then not having an accurate date might not be a big deal. If this information is being used “under the covers” for something important then having an accurate date might actually matter. Until Bluetti tells us what the purpose of having the date and time is, we may never know.
I agree!
Forgot about the data logging, thanks.
That’s why I asked. 
I had the 13th month issue pop up as well. And when I punched in the correction, it wouldn’t stick. But an hour after midnight (AM Jan 1) I tried again and this time it stuck with no problem. Must be some sort of end of year bug. Did you change each field including the “seconds?” I noticed when I finished by hitting the “seconds” it immediately took me to the main screen and the date and time were locked in and correct.