Well, that I do not know yet. I'd like to find a value such a way that with Mugen 2400 mAh battery, I could keep this location recording on all the time 24/7 auto-starting with a boot up, and still needing to recharge the battery only nightly or more seldom. Someone would choose longer period to have the same with normal 1320 mAh battery.

Maybe once in a half an hour, or two hours, or anything. Maybe even adjust the T-value temporarly shorter if the speed is faster, like in aeroplane or in a car, and slowing it down again when device seem to be still or slow moving.

Maybe an option, to adjust T between min_T and max_T so it fits the X. In a fast moving vehicle the T would go to min_T. When staying in one place or speed in the previous N timestamps has been slow, go to max_T.

Also, to the previous, if in the options accurate GPS position is wished for every time stamp, and in some time the device is unable to get wanted GPS position due it to being inside a building for example, the program would change to shorter intervals (interval T2 chosen in the options) to re-try get GPS-position if network-ID has been changed or not (choosable in the options again).

To have it really usefull, all kind of special circumtances have to be thought how to adapt to work as power saving vs accurate, or as agressively or as nicely user wants.