Days/Months Translation

Hello, I would like to translate days and months, but can’t seem to find translatable string for it in loco translate nor in plugin editor (even though I changed days names in plugin editor frontend is not showing any changes)

Language i would like to translate it to is Croatian even though we already “have” translation for this language I don’t think it’s completed.

Also, don’t you think translation of days/months is such a basic and elementary feature to include as translatable?

Thank you