how old is Bosch in the series?

In the books, Bosch was born in 1950. His mother was murdered in 1961, when he was 11. I don't remember exactly how far ahead they've pushed the timeframe for the TV series, but your math sounds right. Close enough, anyway.

In season 2, ep. 10, around 10:00, running down a tip he just received about his mother's death, Bosch tells the desk clerk at the motel where she turned her last trick he's working "a cold case murder from 1979."

Mother was murdered in 1979 and he was 12. So he should be 49.

"Time is the fire in which we burn."

In the books he was a Viet Nam vet (a tunnel rat), but that clearly would no longer work in the series. The overall time-line of the book series is from when Bosch is around 40 until now, when he has past 60 and is clinging to some kind of career. None of that would also work in a series, for obvious reasons. They've done a terrific job of nailing the character while compressing the time frame.

Very little of what's happened in the first two seasons (if any) included Maddie. But it was a great idea to have her included from the start. It was a bold move, but it makes Bosch more complete, instead of a slow work in progress.

They also changed the specifics about his mom's murder. Even that worked out really well.

Both seasons of this have been pitch-perfect to me as a longtime Connelly/Bosch fan.

always worrying about mundane details in works of fiction...i see they have 2 of my least favorite slease bags in the cast, titus welliver and brent sexton...although probably close to the mark of hitting an la cop persona...i probably won't make it through more than a few episodes before i tire of it

In the books he is is 60-ish, but fit, and it is acknowledged by crime writers that series characters age at a slower rate. For instance Spenser, Robert B. Parker's Boston PI was 50-ish for 30 years. To be a tunnel rat in VN, and Connelly's website says Bosch was born c.1950, which in real time would make him 65-ish and too old to be a credible Det 3rd Grade.

But in this series Bosch says he has been a cop for 25 years, makes sense as he is 50-ish. But how does he get being a SF Military in Afghan ? That happened 10-15 years ago. Was he a Reservist who took some time off to go into combat? Seems unlikely.

Was he SF before he joined the LAPD? That would be in his early 20s or 1985-1990. But USA wasn't in Afghan then. The whole military backstory doesn't fit Bosch anymore, it may have when Michael Connelly created the character and Vietnam, 1965-1975 was still possible.

In the first Bosch novel [The Black Echo 1992] Connelly describes him as 40 years old. Of course things change when you adapt to movies and tv.