I am not arguing that "das Datum = the data", what I am saying is that if you hover over "Datum" it lists "data" as a meaning. If data is a meaning for Datum, why would it say ""Datum" cannot mean "data" in German"? Obviously it can, even if not under these circumstances. I think the English explanation for the error needs to be changed.
The hover translation isn't written by the same people who write the correction sentences. And the people who wrote the correction sentence are right. "Datum" is singular, both in German and in English (and in Latin...), while "data" is plural, so "data" can't ever be a correct translation of "Datum".
I understand that die Daten is the plural of das Datum. das Datum means the date in English - or can mean the datum which is the singular of the data (i.e. a single point of data). (This sense is seldom used in English - mostly we forget that data is plural. I would guess that die Daten can mean both the dates and the data. (Native English, learning German)
In English, "data" (which is as you say a plural word) can be used with either a plural or a singular verb. "My data are private". "The data suggests there is a trend."
However, in German, if I am right, only the plural works for "data". I.e. you only use "die Daten", "meine Daten", etc. You never use "das Datum" in that sense, only when it means "date".
Can a native or proficient speaker confirm this?
That... depends on what you mean by the English words?
das Datum/ die Daten = the calendar date/(s)
(das Datum)/ die Daten = digitally stored information on a computer
die Dattel = dates that grow on trees
die Verabredung/ das Rendezvous = I have a date with a girl tonight
der Termin = my job interview begins at ten