Every time you connect to https://banglejs.com/apps/ the watch time is set by that website.
... as long as "Always update time when we connect" is not switched off, like on my PC (I did not do this).
I reset my GPS chip to factory settings with
and still got a time within a second.
I think as long as there is a satelite in view, it will also find the time.
... or the AT6558R has a RTC inside that's not affected by a reset to factory settings and only loses time with a flat battery.