Which is correct date?

[LizzieL]

My OH's great uncle was killed in WW1 in 1917. We have the letter from his CO to his father (OH' great grandfather) which says he died on 24th August 1917, but CWGC website says he died on 23rd. Only a day difference but we wondered which was most likely to be correct.
Any thoughts, please?

[MaxD]

The war diary and other records may hold a clue, what was his unit and name?

MaxD

[LizzieL]

Thomas Livermore - 10th Bn Durham Light Infantry

[jim1]

The 10/DLI were involved in a 3 day action in & around Sanctuary Wood from the 22nd.-24th. Aug. 1917.
They suffered 355 casualties with 46 dead (probably more from wounds later).
Most of these were from shelling including gas. In the late evening of the 23/24th. they were shelled again, this lasted past midnight so it would be difficult to say exactly when a man died during this period. So may have been late on the 23rd. or early on the 24th.
The Batt. C.O. gives a 12 page report of the operation.

[MaxD]

The Register of Soldiers' Effects also gives 23 August.  This would suggest that the official record from which that and the CWGC got their info had that date. 
I agree with Jim.   That the CO, who had the unenviable task of writing to perhaps upwards of fifty families, and that from just this one engagement, has quoted a different date, is understandable.

MaxD

[LizzieL]

Thank you both, we'll probably never know for sure. The letter says the early morning of the 24th, but that may be when the body was recovered and he actually died the night before.

[MaxD]

That is absolutely the right way to look at it.  The way it works is that his platoon commander would sit down with the sergeant after the action and try to complete his casualty list to be passed up the chain of command asking - - did anyone see Private Livermore fall and when was it? Easy enough if there were very few casualties but overnight when many fell, obviously prone to error.

MaxD

[jim1]

The problem with shelling is that it could last for several hours & with men taking cover in trenches & shell holes it's difficult to know what's happening elsewhere. It's only later (on this occasion the 25th.) when they went into reserve the full picture became clear.