Anyone know what is creating commits with bogus dates?

Hi,

I wanted to report that we seem to have a number of repos in the wild with bogus (as in "won't even parse") dates.

I first discovered such a repository in the wild a while ago with rails.git. It has a commit with a recorded timezone of "+051800" for both author and committer. Everything else about the commit looks fine. See https://github.com/rails/rails/commit/4cf94979c9f4d6683c9338d694d5eb3106a4e734.

Some google searches at the time turned up a few other examples, all with the same "+051800" issue. I put a special workaround for it into filter-repo because I figured it was slightly prominent but probably limited to that special timezone. The fact that it was six digits but the last two were zeros made it seem not quite as bad as it could be.

Recently, I've gotten a few reports of commits existing in live repos with other forms of breakage. Dates that correspond to roughly a hundred years in the future, and with timezone specifiers that are either 7 or 8 digits long and no leading or trailing zeros. See https://github.com/newren/git-filter-repo/issues/88.

Is there rogue software somewhere creating some bad commit objects? Does anyone have any idea what might be causing these? Any suggestions on the right course(s) of action?

Right now, I'm leaning towards saying fast-import is right to bail on these, and maybe I'll investigate having filter-repo waste some cycles to try to detect these and report more helpful errors (though I really want to avoid full sanity checking as that's expensive). If I go that route, I'll probably make it link to the example command I provided in that bug report showing users how they can use filter-repo to fix those problems. Does that sound sane? Anything I'm missing?

Thanks, Elijah