NSIS SetDateSave error

Question

I'm using the flag "SetDateSave on" ( default value in a .nsis script ) in order to preserve the Last Modified value of future installed files. The flag works correctly on nearly all files, but for some of them the "Last modified" date is 1 second before the real date. Why this happen?

I'm using NULLsoft 2.51.

Answer 1

Not all filesystems have the same time granularity, FAT only has two second granularity. NSIS tweaks the time a little bit so date based overwrite comparisons work better.