How to transfer photos wirelessly without losing file date and time
If you mean by "transfer photos off an Android" to "transfer from android to pc" i use a pc software to reconstruct the file-date from the exifdate (exiftools)

for the other direction "from pc to android" i insert the android-s sd-card into the pc so the pc can set the file-modification date.

On my android-4.2 and android-4.4 devices the android-os prevents the manual seting of a file-timestamp so transfering to android device via wifi will not work (at least not with my android devices).

[update 2017-02-21]

i have programmed a batch with exiftools : 

 exiftool "-DateTimeOriginal&gt;FileModifyDate" -ignoreMinorErrors -overwrite_original -r -ext .jpg . 


meaning: copy for all *.jpg in current dir and their subdirs: exif-DateTimeOriginal to FileModifyDate