Much thanks for this Granite State Colin, always happy to be corrected. I was not aware of the date taken column, it does not automatically occur in the file manager of my Windows 10. Now switched it on, useful.
However, I am confused by you saying that "All Windows folders set the "Date modified" to be the date the file was added to the folder." I've never found that to be the case when using any Windows or other file managers,
such as Total Commander. I move files around all the time for back-up or simply re-filing and they always keep their date modified as when I or someone else last saved them, not when they were moved. Indeed even re-naming them using the file manager does not
result in the date modified changing. If the file was last saved in say, 2016, that is the what it keeps saying.
To add to my confusion, when I turned on the date created column in the file manager in a folder of photos it showed those dates correctly. However, when I copied a couple of pdfs into that folder their date created
became today's date but their date modified remained the 2016 dates when they were last saved?? Presume this change to date created is because was a copy not move. This would accord with your observation. And I would note that if I moved them from where they
were to the folder of photos they kept their original creation date.
As an aside I also note that if I save an attached file from Outlook to a folder it remains with date it was uploaded as an attachment, eg. if some sends me a file created in 2017 as an attachment and I save it to a
folder it remains showing as modified in 2017.
So I guess, to reiterate, it has never been my experience before Onedrive that moving or copying files around between folders created changes to their dates in the date modified column. Yet I don't doubt your observation
either, perhaps what date modified actually captures is variable and there is some hidden away setting governing it?
To return to Onedrive use generally, I am using Onedrive through the browser and have not been able to figure out how to change the columns it shows, so the problem of it using date modified as date uploaded to Onedrive remains for files that are not photos.
Because it is important that files I use can be shown by the dates they were last modified and saved this makes Onedrive as I presently understand it quite useless for my purposes. Indeed it is a dangerous hazard, since the act of syncing could potentially
destroy my ability to discriminate between groups of files or single files by date. It may be the only safe way to be involved with Onedrive is to always have a separate back-up on a hard drive not connected to it, an absurdity.
Total commander has a plug-in that allows interfaces with cloud storages, as some point I will explore whether that might provide a solution. I've always found TC much superior to Windows file managers, so hopefully it will come through again here.
First, oops, I miswrote that and you're correct. I confused "Date created" with "Date modified." It's the "Date created" that should be set when a file is added to a new volume (I think it will keep the original Date created if you just move it from one
folder to another on the same volume, but I didn't test to confirm that). This is how you get what you described where the "Date created" is newer than the "Date modified."
I just tested with a file I had received earlier today in Outlook. I just dragged it from Outlook onto my Desktop and both the Date created and Date modified were set to the date/time that I copied it. This surprised me that the "Date modified" was also
changing. I tried another file I received in Outlook yesterday and got the same result. I'm not sure if this is a change with a recent Outlook update or a change in the OS handling of files in Windows, but I would expected only the Date created to change.
OneDrive can certainly be used online-only (with a free TB of storage included with every Office install, it's an attractive deal), but the real value comes when using with Windows 10. All the date attributes of Windows are preserved, even if all are not
visible in OneDrive. I don't believe it breaks the "Date modified," only the "Date created" (this is what a wrote wrong earlier -- confusing "Date created" with "Date modified" in contrasting with "Date taken"). Date created is always subject to a rest when
moved or copied to a new volume, and OneDrive would count as a new volume.
I haven't tested this, but it's possible that if you select OneDrive to be your Documents, Desktop, Pictures, etc. store (set up through the OneDrive application in the System Tray -> Settings, not through the registry or other non-supported mechanism),
that it will preserve even the "Date created" field across all computers sharing the same OneDrive system folders, because it will treat the OneDrive drive as the volume, and the same volume on all your systems.