JM: Thanks Jerry Friedman for the link to your Pale Fire timeline, a fascinating reading for those who want to follow the events in the novel from a space-time perspective.[ "A Pale Fire Timeline" <http://www.libraries.psu.edu/nabokov/friedman.htm> ]

I isolated the commentary in which you marked an apparent discrepancy  "July 5, O. S. or N. S.
Prince Charles Xavier Vseslav is born (n. 1–4, n. 433–434, I.). The difference between his age and Shade’s is seventeen years, not sixteen as Kinbote says to Sybil (n. 181), an apparent discrepancy."
I also marked your perceptive relation bt. Gradus and O.S and N.S. Jakob Gradus (henceforth “Gradus”) is born, apparently in Riga (n. 17, 29, I.). Both Zembla (n. 71) and Latvia used the Old Style calendar at the time; starting in 1900, July 5 O. S. was July 18 N. S. [KP doesn’t discuss the Old Style and New Style calendars.]  You add: Jan. 7–13 (Dec. 25 to 31, O. S.) and {Maybe on Jan. 1 New Style, Zembla adopts the New Style or Gregorian calendar (n. 71).}.

Checking your instructions about Charles X: for the 17-year difference 

John Shade was born in 1898. So, 1898+16= 1914, not 1915  (the same mistake reappears when we analyse the NYT episode with Gradus and Kinbote and my original calculations were correct* and I bungled them later).

 

If the sixteen-year difference doesn't hold for Charles Kinbote. his slip about Shade's age can be very significant here. However, if we accept it as correct, it might lead us to assume that (as JF suggested it to be a possibility) Kinbote was lying to Sybil about his birthday having taken place in July 5. CK must have been born before that day in 1915 - but then, lots of other things would've been displaced by this assumption -  unless he had Zemblan time in mind all the time (?). **

 

 

 

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* - "John Francis Shade (born July 5, 1898, died July 21, 1959)."  Shade was 60 in July 1, 1959, whereas Gradus, at that time, was 43 (he'd be 44 four days later)  We learned that the time difference bt. CK and Shade was of 16 years, then in July 1 Kinbote would be... (60-16) 44.  However,Gradus, in July 1, was still aged 43"  .

 

** - Shade beagan his poem, in New Wye "at the dead center of the year, a few minutes after midnight July " ..From note to line 171 we read the hour of Gradus's assignment to kill Charles Xavier and it takes place. in the same date (not time) in which Shade began his poem, in Onhava (Zembla): "We place this fatidic moment at 0:05, July 2, 1959 — which happens to be also the date upon which an innocent poet penned the first lines of his last poem"