I think the idea of a "date" is different around the world. In the US it seems, from watching movies and other pop culture, that there is a (okay I exaggerate a bit) "formal declaration" that a meeting is a "date", meaning we check each other out for compatibility, while over here, people (boy/girl, but also boy/boy or girl/girl) can just meet and have a fun time without any pressure. Disadvantage though if one side thinks this will lead to something and the other that not.
I still wouldn't use the term "date" for father/daughter (or other family) outings, but many people do, and it can be entirely innocent.