"Is your day really improves?" is just flat out ungrammatical in English
I am not a native English speaker, but come on... "Is your day really become better?" is correct whereas "has your day really become better?" is not? Sound wrong to me
I don't think you'd say this in English. I'd say "Has your day gotten better?/Has your day improved?" or in the present "Is your day getting better?/Is your day improving?"