Looks like the dat file and folders in Archive of V6 are organized according to UTC time instead of local time.
e.g. for +8 timezone, now 2024/04/25 16:xx, the minute data is stored in to min20240425_0009.dat
But the timestamp of each data inside the dat files, looks like local time, based on the calculation method descripted in the API (-0001/01/01 00:00:00 UTC)