&#62; For example, the Emacs repository (the git clone at least. I haven't checked bzr) has commits dated before my birth.<p>Given that both the Bazaar and Git repositories are imported from the same source, they should contain the same commits. The earliest commit in Bazaar is:<p><pre><code>    ------------------------------------------------------------
    revno: 1
    committer: Jim Blandy &#60;jimb@redhat.com&#62;
    timestamp: Thu 1985-04-18 00:48:29 +0000
    message:
      entered into RCS
    ------------------------------------------------------------
</code></pre>
&#62; However, any conversion from git is going to have to retain full history.<p>Full, except for the bits of it that Git discarded.