As for my dating of the book, I relied on a few things. One it's generally been assumed that the Enterprise had been built 20 years before the framing parts of "The Menagerie", and, two in "The Menagerie" Spock says that the events of "The Cage" take place 13 years earlier. So I've got the years 2246 (Enterprise built), 2253 (The Cage) and 2266 (The Menagerie). Now then in "Vulcan's Glory" it is mentioned that the story takes place only 2 years after construction on the Enterprise has been completed. So that would place it in 2248.
I just double-checked my TOS Chronology. I misremembered which year I'd put
Vulcan's Glory in. I actually put in 2254, maybe a few months before "The Cage." My reasoning was largely based on the biography of Spock that Number One gives during the crew briefing with Pike. Here are the highlights from my timeline:
-Mar. 2230 - Spock is born on Vulcan (38 years before "Amok Time" in 2268, based upon Leonard Nimoy’s age.)
-2237 - Spock bonded with T'Pring at age 7.
-Mar. 2244 - Secret launch of the
Enterprise in the
Final Frontier novel. (based on Jim Kirk's birthday)
-2246 - Spock enters Starfleet at age 16, after choosing not to enroll at the Vulcan Science Academy.
-2248 - Spock's scheduled marriage to T'Pring (6 years before VG.)
-2249 - Spock graduates Starfleet Academy after 3 years on the accelerated Vulcan course. Amanda attends her son’s graduation ceremony on Earth. (She states it's been "5 years" since his graduation in VG.)
-2249 - Ensign Spock begins 3 years as an assistant science officer on a space cutter in the Sol system.
-Late 2250 - Christopher Pike promoted to Captain. Number One becomes Christopher Pike’s first officer. (She's been Pike's first officer for 4 years, first on the
Yorktown and then on the
Enterprise.)
-Mid 2251 - While on a visit to his parents in Mojave, Captain Christopher Pike is introduced to Janeese Carlisle by mutual friends. Pike and Carlisle soon become lovers. (2 & 1/2 years ago, according to VG.)
-Early 2252 - Spock (age 22) promoted to Lieutenant J.G. & serves on the
Artemis as third officer & science officer.
-Late 2252 - T’Pris’s husband, Lt. Sepel, is killed in a violent alien encounter on Lindoria while both are serving the USS
Musashi. (T’Pris has been a widow for “just over a year” in late 2253.)
-Dec. 2253 - Christopher Pike learns that his lover Janeese Carlisle has fallen in love with one of her instructors at Starfleet Academy.
-Late Dec. 2253 - Spock (age 23) returns to Vulcan for the first time in nearly 8 years. He agrees to delay his marriage with T’Pring until the time of his Pon Farr. (Month & Spock's age given in VG.)
-Late Dec. 2253 - Spock is promoted to Lieutenant & transferred to the
Enterprise as second officer and science officer. Lieutenant (J.G.) Scott (age 33) transfers aboard the
Enterprise as an assistant engineering officer. (11 years, 4 months & 5 days before Kirk takes command of the
Enterprise in April 2265.)
-Jan. 2254 - The main events of VG. (2 weeks after Spock arrives on the
Enterprise.)
-2264 - Sarek & Spock break their silence. Spock visits his parents on Vulcan. The visit is a strained one because of Sarek’s disapproval of Spock’s career choice. (This was a bit of conjecture on my part, as Amanda says in "Journey To Babel" that Sarek & Spock have not spoken as father & son in 18 years, but she
also says that Spock has not been home in 4 years. If you add 4 years to their 18-year estrangement, it allows Spock’s service record to stretch back to 2246, which jibes with
Vulcan’s Glory.)
I don't remember references to the age of the
Enterprise in the novel, but I'll keep an eye out for them if I ever go back to my
Trek timeline.