Copy file from computer to Android device — maintain modified date

I'd like to copy some files from my Mac or from a directory in my Dropbox to my rooted Android phone. Easy enough. But I need to maintain the modified dates and times for those files once they're on the phone. I have not found a way to do that. All files copied onto the phone take the time stamp of the moment they were written to the phone. I've tried adb push, file copy from the TWRP file manager, Dropsync, ftp from my computer to the Android phone. Copying files to an external OTG flash drive preserves the time stamps, but when I then copy from the external flash drive to the internal one, the modified time becomes the current one. I've tried an ftp server on the phone that supports MFMT, which I know little about, but am under the impression can preserve time stamps. Nope. The phone doesn't support a micro SD card, so I can't try that.

Any ideas of something that might work?