"And quarter" is a commonly used phrase that denotes a quarter of an hour past the hour. There are several synonyms for this phrase, including "fifteen minutes past," "a quarter past," "a quarter after," and "a quarter past the hour." These synonyms are typically used interchangeably in conversation and in formal writing, and they all convey the same meaning. While "and quarter" may be the most commonly used phrase, it is important to consider using other synonyms to add variety and interest to writing or conversation.