Here is the schedule for EverQuest's 16th Anniversary events. This information was posted by Prathun on the EQ Forums with the disclaimer, "Note that dates may change, and often do, but we are reasonably certain that these are firm and should not change much."

You can find an overview of all anniversary events (and "non-anniversary anniversary events") on this quest page. Also posted is this event schedule for 2015:

February 25 to April 8 - "War Games" mission in Plane of War (6 weeks)
March 16 to April 27 - 16th Anniversary Player-Designed Missions (6 weeks)
March 18 to April 1 - Brew Day (2 weeks)
March 25 to April 8 - Bristlebane Day (2 weeks)
April 1 to April 15 - Stomples Day (2 weeks)
April 15 to May 27 - 14th & 15th Anniversary Player-Designed Missions (6 weeks)
April 29 to June 10 - 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th, & 13th Anniversary (6 weeks)