aggriversary 

Pertains to marital milestones of the contentious variety. Pretty much self-explanatory.

After 11 years and 363 days of constant bickering, John and Mary were preparing for their 12th wedding aggriversary

aggriversary by jdogdaddyw July 22, 2013

Angryversary 

The anniversary of when something happened that made you angry.

Today is the 1 year angryversary of when my "friend" punched me in the face.

Angryversary by Flik off February 27, 2021