If two revision have the same rev_timestamp, these are show in inverse order in page's history and in user contributions.
The edits with timestamp: "2015-10-06T09:02:22Z" have ID 255174636 e 255174637:
In page's history:
Please use the same sort order.
- T4930: Edit history is based on timestamp while diff prev/next links are based on revision id
- T44296: page history shows unreviewed revisions, reverts in wrong order
- T46841: Contributions appearing out of order
- T48508: Non-unique value is used for paging on some pages/T200354: User contributions is incorrect at the same timestamp
- T91883: prop=revisions sorts by rev_id, not by rev_timestamp