And here you have the problem of the historical Jesus in a nutshell. We have multiple versions in the gospels, all slightly different. Also, over the years, the wording may have “evolved”. So exactly what was meant to be recorded is murky and debatable.
The speculation is that the original was written by someone, or was recited verbatim as oral history; and each gospelizer in turn wrote the bits that he thought were important, in his own words, from an oral source or lost writing. Decades after the fact, the nuances of the original oral history may become lost.
The logic is that paternal lines are everything, and motherhood lines rarely mentioned. To single out the person by their mother’s name rather than mention just their father’s would most likely be an insult, calling attention the a paternity issue.
Was this what the original observers said, and was it recorded almost by accident so an insult was instead viewed by later adherents as an affirmation of holy pedigree? The mention of family suggests this is more authentic, not a centuries later edit that venerates Mary. Whole books could be written debating points like this.
And this is the case with everything Jesus. Records contradict each other even within the same gospel, much was written down decades if not a century later, memory can be faulty, and edits after the fact to advance theological viewpoints confuse things further.
So the timeline is as precise as it’s going to be. Somewhere within 10 years or so of the Year Of Our lord is the actual Year Of Our Lord - probably. And probably earlier not later.