Dan: Not sure if this has been posted but James Bowles, the "Communications Superviser" for the DPD, has a long piece linked below that goes over in some details the time stamps.
See the section titled "Reference to the Times and Recordings". Some of it - more than some - is over my head but it might help.
Link: https://jfk-online.com/bowles1.html
If you read it, read carefully. It doesn't mean what Martin would like you to believe.
When you boil it down and winnow out the irrelevancies, the FUD, and the hypothetical worst-case scenarios, you have two statements by Bowles that sum up the situation:
1.) "it was not uncommon for the time stamped on calls to be a minute to two ahead or behind the 'official' time shown on the master clock" [note defensive use of litotes here, by the way]
2.) "When clocks were as much as a minute or so out of synchronization it was normal procedure to make the needed adjustments."
So Bowles says the dispatcher clocks were kept within two minutes of City Hall time, and also within a minute of each other. The dispatcher clocks are consistent to within a minute, which is the important thing. I've already noted earlier in this thread that the timestamp data from the channel one and two demonstrate the dispatcher clocks were within a minute of each other that day. Frances Cason, a telephone operator in the DPD dispatch office, also said that the clocks were kept within a minute of each other. It's not perfect agreement between the different clocks, but they have don't have to be exactly in sync in order to be useful for our purpose here. And, yes, things would occasionally break down or otherwise get out of that within-a-minute sync, but those occasions were exceptions. You can claim Nov 22 was one of those exceptional days, but then you need to present evidence for it. Bowles himself was the supervisor of the dispatch center. Later, he spent a great deal of time pouring over the Dictabelt when he prepared the original channel one transcripts. And yet, he can't point to a single such exception. Imagine that.
As for the other timepieces involved in this desultory little play:
Bowley is quoted by "Into the Nightmare," saying his watch could have been five minutes off.
Markham's "time" is only an estimate offered well after the fact by a woman who didn't know what time her bus was supposed to have shown up. An estimate based on her observation of a laundromat clock
at some point before she set off to catch a bus. She's just guessing.
Lottie Thompson was the Methodist Hospital ER nurse whom Martin brings into the conversation from time to time. In the 70's, she told Earl Golz that the clock in the Methodist ER was 15 minutes behind on November 22.
If you want to pin your hopes on any of these timepieces agreeing with "real time", good luck. You'll need it.
On a related note, it's worth noting that Callaway's attempt to use the Car 10 radio begins about two and a half minutes running time after the beginning of Bowley's transmission on the channel one recording. Callaway's transmission had to have occurred shortly before the ambulance's arrival but the Dudley Hughes ambulance logs showed that it arrived on scene at 1:18 their time, so the DH clock has to be behind DPD channel one time by a minute or two .
