Hour Names in the Local Language (Declension)

In a block with a list of posts, the English original has eg “8 HOURS AGO”. Now, “8 HOURS” is automatically translated in my language (Czech) as “8 HODIN” (nominative like in “It is 8 hours now”). The word “AGO” is “PŘED” in my language. But the complete sentence in my language is “PŘED 8 HODINAMI” (I think instrumental case, like in “Before 8 hours”). But the template displays “PŘED 8 HODIN” which is a wrong grammar in Czech. How can I make the template to display time in a proper grammar for my language? An example of proper grammar (differs for different numbers): “PŘED 1 HODINOU”, “PŘED 2-x HODINAMI”. It is similar for seconds, minutes, days…

Thank you. I know this part of the theme, I have already switched it to Czech. But there is nothing like “hour” or “minute” or “second” there, so it can not be translated this way at all.

I solved it by editing the templates and entering the “published” date.

After some time, this is still not solved. Somewhere I put just the publication da, somewhere I still need “before XYZ”. It is interesting that days work, but hours/minutes/seconds are wrong. It can not be translated from theme panel, these things are not there.

I solved it with JavaScript that just rewrites the strings on the fly. But it can not be solved otherwise, not with child theme, nor with translation (not even with po/mo). Please, tell to theme authors to add these things to theme translation.

Here is the part of the website I am talking about: https://imgur.com/a/nYpDqum now, the strings are OK, because I am rewriting them by JavaScript.