Maybe?!

You can certainly argue that the panels should be organized this way or that way. We went through a whole bunch of iterations before we got to the current formulation.

It's not simply a matter of moving that one panel up a level, though - the top level is quite heavily populated already, and the top level has groups and you'd need to fit Date & Time into somehow.

We're certainly open to suggestions, but they'd need to take the whole of Settings into account.

Conceptually I do think that Date & Time fits with the other panels that are under Details - they're all very system-y. Also, Date & Time isn't something that users should have to touch all that often, since they should Just Work™.

I think what Allan says make sense about automatic adjustement and ideally, the user won't have to touch it.

The issue IMHO is more about the labelling of this section, being "Details". It doesn't seem that Date & Time or User managements are "Details" (or at least, it doesn't translate well in French for non native speakers).
Also, there is the section "Details" with the first panel being "Details".

Maybe it would better just to rename that section and as such, all of this organization would make more sense? (Something closer to "System" as you tell yourself that all of those are system-y?) ;)

As a reference, my android 5 phone has the following categories: Wireless & Networks, Device, Personal, System.

Users is under "Device", "Date & Time" is under "System". "Language & Input" is under "Personal".