From the announcement post:
Unfortunately it looks like the boosted rates only apply on official servers, so we are out of luck there.We couldn’t let our fifth anniversary pass without an in-game event to accompany it! Bring out your party hats, because from June 11th to June 24th, ARK will be celebrating the memories we’ve made along the way. In addition to Tropeognathus making its grand debut, we’ll be introducing 5 new chibi’s to collect. Looking to complete your chibi collection? A brand new feature for this event allows you to trade 4 for a new one in the forge.
Throw a surprise party for your tribe-mates with the new pop-out birthday cake structure and have a get-together with your tribe wearing party hat skins from prior events!
This event can be manually activated with the server arg parameter: -activeevent=birthday
Dates: June 11th to June 24th
3X Breeding (mating interval, egg hatch speed, and maturation)
4X Player XP
5 New Chibi pets
Party Dodo (Harvested to get cake slices for event content)
Pop Out Birthday Cake Structure
Here is a good video that highlights the new birthday content as it applies to our server: