The dates are formatted MM-DD-YYYY (e.g. the most recent digest for this instance had subject
[Discourse Meta] Digest for 03-21-2015), which isn’t correct everywhere. I guess it may be particularly jarring on a non-English-language instance where there’s little connection to the US and its date format.
One solution would be Remove the date bit from the digest emails subject line .
(I personally think this is fairly minor (even as someone from outside the US), but others may find it more annoying.)