This is basically the same thing we were doing before. See [WithCommitHeaderEnv](https://github.com/spraints/git-tfs/blob/f3e035ced3fd8373c147aa23cc1c420b304ec07c/GitTfs/Core/GitTfsRemote.cs#L599) and [FormatForGit](https://github.com/spraints/git-tfs/blob/f3e035ced3fd8373c147aa23cc1c420b304ec07c/GitTfs/Core/Ext.cs#L99).

> I thought TFS return local time and new commit time (after rewriting to lg2s) is correct one.

@KindDragon - IIRC `logEntry.Date` is already adjusted to be UTC. This just makes sure that libgit2sharp knows about it.