Someday or One Day?

Which One is it?

Japanese has two words (among others) to describe the concept of ‘one day’ or ‘some day’.

Ituska, meaning ’one day in the not too distant future’ is wishful thinking. It might get done, but poorly so.

Izure seems to be the better of the two because there is an air of this one getting done at some intermedia restaurant. It might take a while to get round to it, but it will get done.

So, someday or one day? Which one is it?