Trade directories

A librarian in Manchester told me early nineteenth century ones were
published in January and the details collected the previous year. Is this
correct? E.g. Pigot's Directory of Manchester 1817 would describe 1816.

What about later e.g 1890's and 1900's? Were Slater's published early in
the year? I'm trying to write mini-biographies of my ancestors year-by-year
and not sure whether to record details from directories as describing the
year they were published or the year before?

Ron...

The 1856 London Kelly's is dated 7 November 1855

1819 Post office says get your updates in by Mid october 1819 for 1820
edition

1805 Holden triennial talks about an addendum to be published in April 1805

So I would think for most directories deduct a year

Hugh Watkins...

yes several post mortem entries known to me in my trees

particularly for businesses

use the convention before (date of event)

just if you have a baptism
all you know is that the birth was before that date

as much as 15 years sometimes

telephone directories
have a closing date for the next one

Hugh W