File modification date does not work

I have just installed LibreOffice
I use modified date in my writer documents,
Insert - Field - More fields - DocInformation
Type: Modified
Select: Date and a format.
A narrow gray rectangle is inserted.
It is the same for modified time.

When I save the document there is no change.
When I open and then save an old document,
the date is removed and replaced by the gray rectangle.

Do I need to do something more to make it work?

I’m on Windows 10 Home, version 1909, installed just two days ago.

Do I need to do something more to make it work?

Likely use ODF file format?

Sorry, I don’t understand the comment. LibreOffice is using odf format.

Hi. It works for on LO Version: (x64) on Win 10 Pro. As soon as I save, the field updates itself. One thing that might help is filling in a user name at Tools | Options | Libreoffice | User Data. While you have the options window open it might pay to check that the date acceptance pattern under Language Settings is populated. Finally, I usually reboot after installation. Windows 10 Fast Start doesn’t shut down the PC so either turn Fast start off (first thing I do with a new PC or sometimes an update) or select Restart which I think does reboot it.

Thanks for the tips. Sadly none of them worked.
Could it be some setting in Windows? I guess LO is asking Windows for modified date and time (modified time behaves the same as date in LO), and Windows does not return this. (Although File Explorer shows modified date and time.)

After changing some region and date-time settings in Windows, and restarting LO in between, without success, I finally uninstalled LO, and removed a folder I found in C:…\AppData\Roaming. After reinstalling LO modified date and time is now back.

My conclusion is that

  1. not all combinations of region and time settings in Windows and LO work.
  2. it’s the settings in place when LO is installed and/or started for the first time that determine what works.

    Anyway, right or wrong, it’s working again.

I wonder if it was your LO user profile that needed to be reset.

Run LibreOffice in Safe Mode with administrator privileges (click Help | Restart in safe mode) and then check the radio button for Reset Entire User Profile. Click Restart in normal mode.