Modified Time Difference

[orenk1]

I'm using FFS 7.7 on Windows x64 and I synchronized files from MTP (my Android phone) to a local folder.
I then copied the same files using Windows Explorer and compared the two.
All the files were identical but the modified dates were different: the times were 5 hours behind the original times (same minutes and seconds - just hours difference).
This cannot be attributed to time zone because it's more than an hour.
My phone and PC are on the same time zone.
Why does this happen?

To be clear: if you look at the files in Windows Explorer the "Date" column seems OK (it probably picks a date other than Modified) but if you look at specific properties, the Modified field is off by several hours.

Thank you,
Oren.

[Zenju]

What is the time as shown by Explorer on the Android device and what are the times of the files copied with Explorer and FFS? Screenshots?

[orenk1]

Example:
Filename: 20151216_213334.jpg
EXIF Date Taken: 16-Dec-2015 21:33

On device (viewed using ES File Explorer):
Modified = 16-12-2015 21:33:36

On Windows - copied by FFS:
Modified = 16-Dec-2015 16:33

On Windows - copied by Windows Explorer:
Modified = 16-Dec-2015 21:33

I read that FAT stores dates in local time zone and NTFS stores date in UTC. The files are stored on a FAT SD card and Windows is NTFS. I'm on US Eastern Time, which is UTC-5, which may explain the difference.
However, Windows knows how to copy the date attribute as-is, and FFS shows the difference.

[Zenju]

Windows Explorer isn't consistent within itself: the modification time shown in the details list is calculated differently than the one shown in MTP file properties: A different result is shown for files from a DST interval distinct from the current one. So it's not clear which algorithm to choose.
The first algorithm however has the nice property of generating stable local times independent from DST settings, so I've chosen this one. Let me know what you see with the new FFS version:

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[orenk1]

Thank you for the response. I tested it on FFS 7.8 and I'm glad to report that the times match perfectly! I'd like to take this opportunity to say what a great software FFS is.

I understand that there are two options so perhaps this should be a program setting, but I think that if there is no setting then the way that's compatible with Windows Explorer's copy function is preferable (i.e. FFS 7.8).

Of course, DST is important, especially for the comparison function, so I tested FFS 7.8 on files from the summer time. Here is an example:

Filename: 20150830_171426.jpg
EXIF Date Take: 30-Aug-2015 17:14
Modified - shown on device: 30-Aug-2015 18:14:26
Modified - copied by Windows Explorer: 30-Aug-2015 18:14
Modified - copied by FFS 7.8: 30-Aug-2015 18:14

So the times match between all three Modified fields, and they reflect the DST time (which the device was on, I assume), while the filename and the EXIF data show the time without DST (which is weird but that's how my Samsung Phone behaves).

BTW, I think that in addition to the options of "today", "this month", "this year" and "last x days", it would be beneficial to have a "from date-time" option, so users can copy files created since their last copy run (the "time" part makes that difference).

I believe FFS uses the Modified time for the comparison. I think that once the files are collected, it's a simple comparison between Modified Datetimes (to see who's new) or between the modified datetimes and the Windows datetime (for the filtering function), right?
I wanted to test the filter function (all the files I'm updating are new so there's no comparison). I needed a file created/modified during DST at 23:xx, which would mean a date change, but I didn't have one.

Thank you so much!