In the UK we don't have to write our date of birth on our CVs. The reason for this is that employers may discriminate on the basis of age. However, age is not an indicator of whether or not you can do a certain job. The only important factors to consider are skills and experience. For that reason, we also do not have to put other personal information like religion or ethnicity. It is all irrelevant!
However, if you want to put it, I would suggest:
Date of birth: 7th July 1990