I am using Windows 10. I open an old file, in an old folder, that was created in MS Office, probably an older version, i.e., prior to the Office 365 I am now using. I then e-mail the file to someone via Outlook, then close the file without saving (actually, it may even happen without e-mailing the file, just opening it and closing it without saving). The file date stays the same, as it should. However, the folder's date becomes today's date - permanently. This ruins my ability to search the folders by date. This anomalous behavior does not seem to happen if the file I use is not an Office file, e.g., a PDF. I also note that I have a file sharing application for some of my folders and, when I log onto that, via the web, it still has the correct old date for that folder. So, if seems to be some sort of Windows problem. In fact, I re-tried this for folders that were not part of the file sharing application and they also exhibited the same problem. There are a few posts on the internet from years ago that claim the same problem, but I don't see any solution posted for those. Thanks so much.