Tag wiki Stats - "created" showing with wrong date calculation

Question

In any tag's info page, under the Stats section the created detail is displaying. But the period is displaying wrongly.

For an example the moderator-tools tag was created on 2011-07-31 (also found in the tooltip of Stats), so the tag's duration period should be 5 years, 11 months. But in the Stats section it is displaying as 7 years, 1 month. The calculation is wrong.

I have verified for most of the tags and the period is displaying wrongly in the tag-wiki Stats section.

Answer 1

Welcome to the world of confusing Created stats about when a tag is Created. IMO the information included in your question is not entirely (100%) correct:

• The date of 2011-07-31 19:39 (as shown in the image of your question), is the timestamp of the first revision of the tag wiki excerpt.
• The tag moderation-tools itself, already existed on Aug 8 '10 at 13:11. The proof of that is included in revision 1 of the question titled Synonyms of synonyms should be "collapsed" (which is about 6 years and 10 months after you posted your question, and only 3 months after those 7 years and 1 month as in your question's image). I've not been able to find an even older question (yet ...), but I'm pretty confident that there is still an older question which either used to have that tag, or got deleted already, and in which the tag moderation-tools was first added (with an empty tag excerpt).

Another example

This is indeed a network-wide problem (as in the comment from ahmedus below the question). Consider what happened to the group tag (on Drupal.SE):

1. This question is the very first question (timestamp question was asked), in which the "group" tag was added. I have no idea how to "proof" (via some query/sort) that this question indeed is the very first question with that tag. But I just know/remember that question when it happened (also because it is one of my favorit tags ...).
2. However, only in revision 6 of it the "group" tag got added. So from that very moment on, an EMPTY group tag got created (timestamp of the revision = Sep 13 '16 at 23:51).
3. The next day, at Sep 14 '16 at 6:07, "I" created revision 1 of the tag wiki excerpt fro the group tag, as shown in this revision history.

With the above in mind, have a look again at the tag info page for the group tag on Drupal.SE: the timestamp shown within "created" (= Sep 14 '16 at 6:07 if you hoover over it ...) is the timestamp of the very first revision of the tag wiki excerpt.

Recommended correction

IMO that "Created" timestamp is wrong (or at least misleading) and should instead be the timestamp of the revision 6 of the original question. Or as an alternative (quick win?): adapt the 'Created' label to something like 'Tag excerpt created').