Since today the rare spawns are at a normal standard rate. Either the calender is wrong (it shows rare bonuses till Wednesday) or something is wrong with the spawn rate. I checked that with other players which experienced the same (Antonius Bayle). This is very simple to verify. Maidens Eye didn't yielded any spawns in around 4 hours killing different place holders. That didn't happen over the weekend. Umbral and Maidens spawned them very often at Sagurday and Sunday.