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When copying files from the SDHC card of the camera to a local HDD for storage, I find that sometimes the modified time of files is a hour different. I believe this is because the SDHC card uses FAT32 and the hard drive uses NTFS, and daylight saving time is handled differently between both systems. I am using Windows XP SP 3.

Is there any way to retain the modified time stamp on the file when copied from the SDHC card to the HDD? So for example, if a photo is taken at 19:20pm actual time then the modified date would show as 19:20pm on the hard drive regardless of daylight saving time?

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timestamp is always in UTC. The interpretation of it can be in different timezones and affected by daylight saving time. I think your camera saved the files in UTC and your Windows has a time zone setup and displays those modification dates shifted. I might be wrong - maybe someone else will find a better answer. – mnmnc Apr 1 '13 at 12:04
@mnmnc FAT stores file times in the local time zone (source; 2nd paragraph) whereas NTFS uses UTC (same source). – Michael Kjörling Apr 1 '13 at 12:08
Also, the timestamp's resolution is different on the two file systems. Why are you even relying on something like the modification timestamp? Wouldn't it be far better to use something like the EXIF time field instead? – Karan Apr 1 '13 at 21:36
@Karan: Not too concerned about the resolution, since I am generally going from FAT32 (on camera SDHC card) to NTFS (on local HDD), and so going from a lower to better resolution. The EXIF time field is nice, but not all utilities (e.g. WinMerge) support it and it is not available for all files (.avi for example). Many utilities (and myself) often just look at the modified date, and this is what suffers from the DST issue with different file systems. – Goto10 Apr 5 '13 at 19:15
up vote 0 down vote accepted

My advice would be to just be aware of the issue that FAT32 uses local time and NTFS UTC (as Michael mentions in his comment).

I format drives in NTFS where possible, so conversion between different filing systems is not necessary. However, there are times when FAT32 is needed, such as a camera card (NTFS would not be supported by my camera).

Also, if using utilities to compare date stamps where DST could be an issue, some utilities provide an option to allow for this. For example, the Second Copy IgnoreDST option.

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