I can't seem to find this one in the database or ads. It also looks like a first for the 10BZACD movement.
10K RGP, 23 jewels automatic with date, water proof, 2378 case number.
Forgot to add that it has a date code M4 on back and M3 on movement.
Guy Montag, it's been nearly 50 years but this week I re-read the book! Now I know why your User ID sounded familiar. Are you a fireman too Guy?
In reply to Guy Montag, it's been nearly… by Geoff Baker
No, I'm not a fireman, I just really liked the book as a kid. I'm a voracious reader and the frightening idea of a world without books really left a mark on me. Here we are in 2022 and the book is just as relevant today. I think when I first signed up here I thought I was going to be 'one and done' and just used the first name that came to me as I wasn't really into watches and was just trying to ID a watch I had bought 15 years prior and had been sitting in a desk. But a year and 70+ Bulova's later I probably should have just used my real name :)
- Dave
Based on the case M4 I'd date to 1964.
Accordingly the closest I could find is the Bulova Regatta 23 "W", although the linebook photo dial color is throwing me off that variant.

Model 03516 looks to have changed to the Date King "Z" by 1965.

Both images appear to not be a white dial. "Calendar" was also a used model name for these 23 jewel calendar models.
I don't find any of these as a great match to that white color dial.
In reply to Model 03516 looks to have… by Andersok
So still a Regatta 23 in 1964?
In reply to So still a Regatta 23 in… by mybulova_admin
Yes
so.....1964 Bulova Regatta without a variant, right?
1964 Bulova Regatta and assume the variant is A with the linebook just being shading on the white dial but will go with no variant until we can confirm dial color.
1964 Bulova Regatta - no variant for now.