In written English, yep it is fine. If you are speaking, you would add the article 'the' 20th of July Americans might say July 20th

Are you asking about written or spoken English? That wording is fine in written English (although American English speakers might prefer "July 20th"). In spoken English, you'd say either "I went there on the 20th of July" (more common in British English) or "I went there on July 20th" (more common in American English).