Member Avatar for DJSAN10

Any file's primary header contains some things which are common to all operating system like entry point function, time stamp etc and then other things. What is the purpose of keeping this time stamp in the header.

Thanks

  • 3 Contributors
  • 4 Replies
  • 464 Views
  • 2 Days Discussion Span
  • Latest Post Latest Post by DJSAN10

Dani AI

Generated

Short answer for : the "TimeDateStamp" in the COFF/PE file header is a 32‑bit value written by the linker that records the link (image-creation) time as seconds since 00:00:00 UTC on 1970‑01‑01. It is not the filesystem creation/modify time (those are separate), it’s the link-time recorded inside the binary itself. See the IMAGE_FILE_HEADER definition for details. (Microsoft: IMAGE_FILE_HEADER).

Why it exists and how it’s used (following up on and ): historically the header timestamp is used as a quick identity token by several subsystems — most notably import binding (bound imports) so the loader can tell whether previously recorded IAT addresses are still valid; older debug matching workflows and some minidump/symbol-matching tools also relied on it to pair binaries and separate debug info. These are documented behaviors in PE-format writeups and practical tooling guides. (PE format overview, background writeups such as the PE articles linked in public references).

What changes if it’s missing/zeroed or not trustworthy: import binding simply won’t be usable as an optimization (the loader falls back to full import resolution), and timestamp-based matching for legacy debug workflows or forensic timelines becomes less useful. Modern toolchains and debuggers increasingly use GUID+age or explicit hashes for symbol matching (and some toolchains support deterministic/reproducible builds that replace timestamps with stable hashes), so the timestamp’s role has diminished in many contexts. (See modern PE debug/repro discussions and tools documentation.)

Quick, practical checks you can run:

dumpbin /headers my.exe    # look for "time date stamp"
objdump -p my.exe          # shows "time date stamp" on many toolchains

Python (pefile) example:

from pefile import PE
pe = PE('my.exe')
print(pe.FILE_HEADER.TimeDateStamp)    # numeric epoch seconds

Troubleshooting notes: if the timestamp looks wrong (nonsense or in the future), it may be unset, deliberately altered for reproducibility, or wrapped as a signed/unsigned interpretation bug; don’t rely on it alone for provenance.

Recommended Answers

All 4 Replies

Member Avatar for WaltP

Which date? Creation? Last Write? Last Access?
All seem important to me, albeit to differing degrees.

And what are you considering a header?

Member Avatar for DJSAN10

Okay, honestly speaking I don't know the exact contents of time stamp.

And what are you considering a header?

The header I am talking about is the one attached by a linker which is removed when a program becomes a process (i.e. brought into memory). Since linkers are operating system dependent their headers differ from OS to OS. But there are a few common things which every linker adds to the header of a (can say COFF) file. One such thing being Time stamp. I want to know what is this time stamp exactly and what difference would it make if this primary header of a file does not contain any time stamp as such

Member Avatar for nezachem

Look , specifically in the discussion of "bound imports". This is the only use I am aware of.

Member Avatar for DJSAN10

Look here, specifically in the discussion of "bound imports". This is the only use I am aware of.

Hey thanks a lot for your reply .I' ll go through the link

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.