This response from TFL:
“They update every 3-6 months, we are just waiting for the data to the end of October to be ready – it should be up by the end of the month. Please note we only release 6 months of data, so if you require historical data please ensure you save the current dataset, as Feb-Apr data will soon be removed.”
I’m seeking clarification exactly what they mean by this!
On the original point, the 6 files now look to have a complete date range, though 29/02-03/03 appear to be duplicate across parts 1 & 2, and there are some very odd records with dates of 1900 and 1901 in I think part 4!