The sun is a potent symbol throughout the world—ancient and modern. In funerary symbolism it is depicted in many ways: as a yellow sphere; as spreading rays of light; as a geometric pattern shaped like a many-pointed star; as lines emanating from a single point outward in a fan pattern. The ancient Egyptians depicted a single ray of the sun as an obelisk in honor of their sun god Ra.
Like many symbols, there is a duality to the sunburst. For instance, when looking at the symbol, it is difficult to discern if it is a rising sun or a setting sun—which leads to its dual meaning. The rising sun represents the resurrection, rebirth, and eternal life. In fact, many Western cemeteries were oriented to bury the deceased facing the rising sun in anticipation of the return of the Savior God Jesus. The setting sun, however, represented death and the end of the mortal life.
So, which do you see–the rising sun or a sunset?
Gravely Speaking 
One also sees the term ‘sunrise’ for the birth date and ‘sunset’ for the death date on monuments. I’m sure you’ve seen this; I saw a lot of this in the African-American portions of the Wilkes Street complex of cemeteries in Alexandria, VA. Thank you for the wonderful images, especially the stone monument.
I have not seen those gravestone that refer to sunrise for the birth date or sunset for the death date. I am going to have to keep my eyes peeled so I can find some, too. The symbolism of the life of a person being compared to the course of the sun during the day is beautiful.
The question of rising sun versus setting sun is a great one… Benjamin Franklin had an opinion about this! At the Museum of the American Revolution in Philadelphia there is a president’s chair in the collection that features a personified sun (carved in wood) that is the same design as we find on gravemarkers. Frankin’s quote is displayed next to this chair and though i don’t recall the exact words, he said that he often wondered if the sun on the chair was rising or falling, but now he knows it to be a rising sun. It’s not a definitive answer, just his opinion, but one early voice in this discussion.