( Already know that Ponybooru 2020/7/5, Twibooru 2020/7/8, Manebooru 2020/7/31 ) >>0 says 2012/1/2, same as Derpibooru. But there’re two possibilities: one is that Ponerpics was indeed founded on Jan 2, 2012; another one is like When did Tantabus.ai be founded?, which means the 2012/1/2 shown by the image is due to importation, and Ponerpics was founded in another year. So, when was Ponerpics founded?
@Background Pony #2726 Archive.org first saw Ponerpics in August of 2020. When I look in the archive it looks like the earliest forum posts were from maybe approximately June 2020, so we know the site already existed at that time but not for how long. Maybe the mods know more.
It was founded during summer of '20 when that derpibooru debacle was going on. The reason the first image has the same upload time as derpi is because it is synchronized alongside the image IDs, all derpi-imported images until May '23 (last I checked) are. Look up the derpibooru threads on desuarchive's /mlp/ archive during summer of '20.