I'm using a file modified date as a base for file names in via C#. My question is what can make the modified date to change?
I actually thought the modified date was the created date first. But the created date is changing when I move the file from USB to harddrive. So I had to use the modified date which has the correct, untoched date.
As I thought when the file was moved the modified date was changed but its actually the created date that is changed in Windows 7 at least.
Is there any use case that may change the date of the file (except unpacking it from a zipped file) surprisingly? Like maybe from DVD to harddrive or something like that?
Best regards
Mr Rob
File properties with regards to the date and time stamps
- If you copy a file from C:\fat16 to C:\fat16\sub, it keeps the same modified date and time but it changes the created date and time to the current date and time.
- If you move a file from C:\fat16 to C:\fat16sub, it keeps the same modified date and time and keeps the same created date and time.
- If you copy a file from C:\fat16 to D:\NTFS, it keeps the same modified date and time but changes the created date and time to the current date and time.
- If you move a file from C:\fat16 to D:\NTFS, it keeps the same modified date and time and keeps the same created date and time.
- If you copy a file from D:\NTFS to D:\NTFS\SUB, it keeps the same modified date and time but changes the created date and time to the current date and time.
- If you move a file from D:\NTFS to D:\NTFS\SUB, it keeps the same modified date and time and keeps the same created date and time.
- In all examples, the modified date and time of a file does not change unless a property of the file has changed. The created date and time of the file changes depending on whether the file was copied or moved.
For more information see KB299648.