Glitch with dates

Recently Numista added new statistics on user profile, which allows to detect, for example, the largest and the smallest, the heaviest and the lightest coin in the collection, etc.
I really enjoy this feature; however, it seems to be a bit glitchy (or is it the catalog's feature?)
In my case, this coin is displayed as the oldest coin one in my collection:
https://en.numista.com/catalogue/pieces122256.html
However, 366 is an Islamic calendar date.
My really oldest one is different.

PS. Just tried to modify the dates on the catalog myself and will see if the admins will approve it.

Coin is fine. It is a glitch on statistics page.

It's not about the statistics page, I noticed something similar on other pages using the islamic calendar and I think I just figure out what the problem is.
When there is no dates visible on a coin, we add a specific entry by checking the "no date" box and adding the issuing years.
However the system don't do the conversion to gregorian for this specific field or simply consider those dates as gregorian, it's the reason why the coins are ranked by undated fals from 658 to 904 followed by the dated fals from 709 to 814 AH for this issuer : https://en.numista.com/catalogue/mamluk_sultanate-1.html

Non dated coins should have their date in the Gregorian calendar. This would remove the glitches on the statistics and other parts of Numista. Feel free to submit a modification request if you see coins with an incorrect date.