“était” implies that the work day is over.

You could say:

Comment se passe ta journée (au boulot/ au travail) ?

If you don’t mention “au boulot/au travail”, that’s implicit in my opinion.

I think this is an american tradition. One can translate it but no french speaker would talk like that.

I wouldn’t refer to work explicitly, but ask, “How is it going?” — Comment ça va ? — or, Ça va bien ? — or just, Ça va ?

If I wanted to ask for a detailed report about work, maybe, Elle était comment, votre journée au travail ?

Ça s’est bien passé, ta journée au boulot ? invites a one word answer (and is familiar, using ta instead of votre).

Note that était is past tense (“was”), which doesn’t match the title of the question (“is going”, present tense).

A better phrase would be :

Comment s’est passée votre journée de travail ?