Hi,
The format of the timestamp in the DispatchStats API will be changing in the near future. It currently is a raw database timestamp[1], which was a mistake. Once [2] is merged and deployed, it will be a properly formatted ISO 8601 timestamp.
[1] https://www.wikidata.org/w/api.php?action=query&meta=siteinfo&siprop... [2] https://gerrit.wikimedia.org/r/#/c/138306/
Thanks, Legoktm