You may have missed which table of recordings I was referring to. Indeed the usual list of recordings available from the TVGOS "RECORDINGS" screen shows recording titles and their time of recording (day of week, date, and wall clock hours and minutes, but no seconds). I referred to the list of recordings that can be seen in one of the 753... diagnostic screens. Find the "Section Recording-Recordings Detail" screen there and you will see on the left that each recording has a 10-digit number associated with it. That number is the Unix time of the recording. It is the number of elapsed seconds from 00:00:00 1/1/1970 until the recording started and is the real internal timestamp of the recording.
You can check that out by taking that number, adjusting it by the offset given in the 753... Clocks1 diagnostic screen. (That will be a negative number, so you actually will be reducing the Unix time - reflecting that you are west of Greenwich.) You can then convert that number to conventional date and time notation using the following web site (precede the next line by http://)
The offset you use must be the one that was in effect when the recording was made. If the recording was made when daylight savings was in effect, but you use the offset in use during standard time, the websites's conversion will be off by an hour.
The resolution of the internal timestamp is in seconds. That is important because instant recordings may not always start on exact minutes, in contrast to manually scheduled recordings which can only start on exact minutes since the scheduling screen only allows input of hours and minutes.
I will admit I do not understand why the time of archived recordings might change after a reset. I intend to avoid resets and want to concentrate on convincing Sony to produce a clock-set solution.
I am still working on a posting covering that, but I wanted to answer your question first.