I have come across the following sentence in Activate Level A2 coursebook by Carolyn Barraclough, Elaine Boyd, Suzanne Gaynor, Megan Roderick, Mary Stephens: 

> 
> I would recommend the Art Museum - especially if *you've got* a birthday.
> 
> 
> 

I have always been taught that we cannot use the verb 'to have (got)' while talking about age: I *am* 18 (years old). It *is* my birthday next month. or My birthday *is* next month. My source of reference here is 'Common mistakes at KET' by Liz Driscoll CUP.

The sentence in question wouldn't have baffled me if there was the word 'party' as in '... especially if you've got *a birthday party*.'

I am looking for a reliable source to read more on the topic as well as thoughts on how natural the sentence sounds and how frequent this usage is in everyday speech.