Longitude in time is a term that is commonly used to help determine the specific time of a location compared to others. However, there are various synonyms that can be used to refer to this concept. One of the common ones is time zone, which refers to a region with uniform standard time for legal, commercial, and social purposes. Meridian time is another synonym, which is used to refer to the time difference between the local time and the prime meridian at Greenwich. Additionally, some people may also use the term time meridian to refer to the same concept. Overall, these synonyms help to highlight the variety of terms that can be used to refer to longitude in time.