"That time" is a commonly used phrase that refers to a specific moment in the past. However, there are various synonyms available that can be used in place of this phrase. Some of the most popular synonyms for "that time" are "the past," "the bygone era," "those days," "the yesteryears," "the ancient times," and "the olden days." Each of these synonyms have their own unique connotations and can be used to convey a different tone or mood in your writing or speech. So, the next time you want to express a particular moment in the past, consider using one of these synonyms instead of the overly used phrase "that time".