It has always been observed the second Tuesday in June.
How to Observe: On this day you may celebrate the lives of your pets that have died. There are many ways you could do this. You could make a picture collage or scrapbook of your beloved pet, or frame a favorite photo of them. You could plant a trees or other plant in their memory. You could also donate your money or time to a place that helps animals. This may also be a good day to view the Errol Morris film, Gates of Heaven.