Ryan Dorseyis celebrating sonJoseyon his 6th birthday.

Dorsey, who shared Josey with late exNaya Rivera, marked the special occasion with a sweet Instagram post on Sunday.

“Two thousand one hundred ninety+ days old,” Dorsey, 38, continued. “My sweet, smart, spectacular boy, every day is a gift, I love you more every day and am so proud to call you my son.❤️💙”

The post comes a few weeks after the proud dad celebrated another one of Josey’s milestones:starting kindergarten. At the time, Dorsey posted an adorable photo of the boy on what appeared to be his first day of school.

He alsoposted throwback photos and videofrom a father-son visit to the Santa Monica Pier, during which the pair rode on the landmark’s iconic roller coaster.

“#TBT (lol) The 1st Day of Kindergarten was a roller coaster to remember 🎢!!❤️,” the actor wrote in the caption.

Never miss a story — sign up forPEOPLE’s free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Riveradiedin July 2020 at age 33 as aresult of a drowning accidentafter she and Josey rented a boat at Lake Piru in Southern California. When theGleestar didn’t return the boat on time, staff found it on the north side of the lake with Josey sleeping in his life jacket on board, but no sign of Rivera.

(L-R) Naya Rivera, Ryan Dorsey, son Josey.Ryan Dorsey/Instagram

Ryan Dorsey and Naya Rivera

“Our boy has grown so much,” Dorsey continued. “He’s such an explorer, so inquisitive. He’s sweet, so funny, and his laugh always lights up the room. He’s an intuitive soul to say the least. To know him is to love him, everyone that meets him is always smiling.”

Calling Josey a “resilient strong kid,” Dorsey added in a note to Rivera that their son “misses you but knows he’ll see you again, and the invisible string is something that’s helped us out during this ever-evolving transition of your time with us on earth that was unfairly & for reasons we’ll never understand cut short … too soon …”

source: people.com