This is one of those questions that really depends on the sensitivities of the particular parents.
Yes, if you choose a previously uncommon name which has recently been used by a celebrity, there are some people who will assume you were inspired by the celebrity. So the question is, how much would that bother you and how would you deal with it?
Some people have the sort of personality that they can just let others' incorrect assumptions roll off their backs, and are perfectly fine with thinking of humorous or polite ways to correct the impression, such as "We had the idea first!".
Other people would be highly embarrassed and upset to be continually asked the question about whether they were inspired by the celebrity.
You have to make a judgment about your own personality here. If you are the first sort of person, go ahead and still use the name like
Sunday or Ever. If you are the second sort of person, it's better to find something else you like. :)