Loaded up Unity Hub this morning, 11th of January, 2021 (a Monday) at 7:13am. Last Modified for the project I was working on shows up as 13 minutes ago. However, I was last worked on that project on Friday the 8th of January at around 3:30pm. Confirmed by checking the last modified stamp in Windows Explorer (and I know I didn't login over the weekend). Unity Hub version 2.4.2
I believe Unity Hub uses project folder metadata to get the Last Modified datetime. Since Windows only has Creation Datetime for Folders (Last Modified only exists for files, not folders), Unity Hub must use the Creation date. Thus, almost always invalid. EDIT: Actually this seems to be a filesystem specific feature and can even be disabled by the filesystem (i.e. NTFS). Reliable solution may be detecting modification dates for the files inside the folder.
Could you please submit a bug using the Bug Reporter within the Hub? Our team needs to look the log files. To do it, go to Account Settings > Troubleshooting > Report a bug
Still Same problem with UnityHub 3.5.0, it should be very easy to solve this problem. Let me do it for you Unity