Feature request. To replicate:
1. Start LibreOffice
2. Click Help >> About
Version information includes build date (and timestamp).
Thank you for your bug report.
Please provide some info how to obtain build date and timestamp.
For nightly builds, the build date and source buildbot details are already included in the development builds.
Official release builds do not need the release date, as they are stamped with the SHA1 build ID of the final commit that is included in the build. That ID can directly reference the cgit log database for build details. All OS versions of a build will have the same build ID. And, for the 4.4.0 build onward, the localization language selected for the install is also now included on the help about panel, as this was judged useful for problem reporting.
The date a build is completed can vary by OS, but will have the same build ID.
If needed, a review of the date stamp of any of the LibreOffice executables on the local system should suffice.
But, for users desiring project build dates in context, an archive for released builds is maintained by the project--dates of each build are available there: http://downloadarchive.documentfoundation.org/libreoffice/old/
And the project Wiki offers the release plan
Clearly a duplicate, but still suggesting won't fix status.
*** This bug has been marked as a duplicate of bug 79438 ***