Change or remove HTML5 placeholder attribute

A "No default value" date textfield widget has a HTML5 placeholder attribute that looks like a real date value. This is confusing in at least two ways: (1) Anyone not realizing that it's placeholder text might skip past the field thinking it's already filled in, or (2) someone might spend 15 desperate minutes anxiously trying to figure out how to clear the field so as to leave it unset.

A gray default color would help, but I don't think there's a non-proprietary way to set that yet. I'd personally prefer to leave off the placeholder attribute entirely, or at least tweak the attribute text to make it clearer that it's an example.