# `SOURCE_DATE_EPOCH` [Thu, 09 Aug 1990 14:25:15 +0000 (1990-08-09)](https://hg.python.org/cpython/rev/3cd033e6b530) [From `git log`](https://reproducible-builds.org/docs/source-date-epoch/) Adding core metadata for `PKG-INFO` to record the sdist's last modification date could be used for `SOURCE_DATE_EPOCH` when building wheels. # Source origin Core metadata to record where the source came from (VCS repo and commit).