time and date missing for files and folders

I can not get the date and time info on files.

In column view this is what it shows about the file: "Last opened" or "modified" info says "yesterday" or "today" but no date and no time.

In list view the date modified is shown but no time.

Using Command-I to Get Info on a file, this is what it shows: "Created:" says "at", and "Modified:" says "at"

This happens with various kinds of files, including Word, Excel, TextEdit, and JMP (a stat program).

This did not used to happen. Have I accidentally modified or failed to set a preference somewhere?

How do I fix this to get date and time for every file?