how to conditional datepicker on Opera browser

how to conditional datepicker on Opera browser

So I read that we should not do browser detection but rather feature detection.

Well how do you go about this one:

I use the jquery-ui datepicker on some input fields; I have php browser detection which determines whether my doctype is html5 or xhtml11, and determines whether my input type is going to be text or date.
Even when doctype is html5 and input's are type=date, I still use the datepicker widget seeing that most browsers still don't have one built in.

The Opera browser now has its own datepicker built in, so when using Opera I'm getting two datepickers: the jquery-ui datepicker and top of that the Opera datepicker. I would like to avoid this.

I don't see how I can do feature detection here ( = whether a browser has a native datepicker), should I just go ahead and test if useragent is Opera and if so not apply the datepicker widget?

John R. D'Orazio