What exactly is FileTime as mentioned below (in .irp)?

        <File14 flags="0">
            <InternalName>\folder\file.ext</InternalName>
            <FullPath>E:\folder\file.ext</FullPath>
    ---->        <FileTime>128515831800000000</FileTime>
            <FileSize>36466</FileSize>
        </File14>

I saw the source code. I see some specific bytes are read from a file stream to arrive at this number. I would appreciate if someone tells me what, why, and how to arrive at FileTime given a file.

I am writing a ruby script to automate .irp creation for my backup purpose. Couldn't figure out what goes into <FileTime>. I am also not sure if there will be a problem if I skip this tag in .irp, and use the project to burn DVDs.

Any information is greatly appreciated.

Thanks for your time in advance,
Ragu

It is a 64-bit number, read more here: http://msdn2.microsoft.com/en-us/library/ms724284(VS.85).aspx

I don't recommend ignoring the file time all together, I believe it could cause problems when creating the disc file system.

Thank you.