Ages of characters in BBCA Dirk Gently's Holistic Detective Agency, and when they were taken by Blackwing.
Sources: the show, the wiki, child development stages, and my presumptions.
Patrick Spring died 3rd August 2016, start date of season 1.
Todd Brotzman: 15/11/1981 DOB, 35.
Amanda Brotzman: 23/10/1993, 23.
Farah Black: 30/05/1995, 21.
I know this is their canonical ages, but I don't think Todd and Farah's make sense.
Todd Brotzman changed in 2011 when Amanda developed pararibulitis. If he were 35, he would have been faking for 9-10 years. Similarly, in S1E8 Amanda calls him a 33-year-old Bellhop, faking for 8 years. In my opinion, that seems too long. I don't think his band lasted for 8-10 years till 2011-12, after he sold the equipment. I think it makes more sense for him to be 30-31, DOB 1985-86. He dropped out of college at 20, then lived off his parents for 5-6 years. The next 5 years, he was taking care of Amanda.
Farah Black applied for the FBI, and the age requirement is between 23 and 36, unless she got some exception. Once she was rejected, she became Patrick's bodyguard, but I assume it was for a year at most, considering she said her applications were 'in contention' (waitlisted). Therefore, she's 24, DOB 1992. Still an uncomfortable age gap.
Blackwing founded in 1988 and lost funding in 2000
The Rowdy 3 were one of the first taken in. Martin, Cross and Gripps seem about 38-40, DOB 1976-78. They were 10-12 years old when taken, which matches with how Riggins talks to them. Vogel is older than Amanda, but still looks young so ~25, DOB 1991. He was likely added in 1999, when he would've been 9.
Bartine "Bart" Curlish was brought in by Mr. Priest at age 13. Probably one of the last to be caught, so 1993-98. To me she seems older than Dirk and Mona, so 36 DOB 1998.
Mona Wilder: Spent six years as a chair before she was brought in. She would've been at least 3 months old, maybe latest 4 years old. She met Dirk in Blackwing, although canon contradicts where Dirk said he never met any of the others, but knows Mona upon seeing her. Taken in 1988-1998, age 24- 38. Her actress was 24 in 2016, DOB 1992. I'm unsure what age I consider Mona.
Dirk Gently is described as in his 30s, putting his DOB 1981-85. I would put him at 32, DOB 1984. His birthname was Svlad Cjelli, which is a Slavic name. His parents were likely immigrants, and lived in a posh area, considering Dirk's accent. Dirk retained such accent and therefore was 7-12 years old before being taken to America. 15-19 in 2000, meaning he was taken in 1988-1997.
Additional angst: he forgot his own birthday because Blackwing would never tell him what the date was, so he wouldn't know when to celebrate it.