You use sometime to refer to a time in the future or the past that is unknown or that has not yet been decided. The sales figures won't be released until sometime next month Why don't you come and see me sometime?
at some indefinite or unstated time; "let's get together sometime"; "everything has to end sometime"; "It was to be printed sometime later
one day, at some indefinite time in the future; at some unspecified point in time