In the Russian language, there are several one-word terms to tell about a person born around the year you were born:
ровесник -- approximately of the same age with you;
одногодок -- born in the same year,
погодок -- born a year or so before or after you were born,
одноклассник -- the one who were with you in the same grade at school,
однокашник -- college/university mate who entered the educational institution in the same year you did it (the usual age to begin a higher education being 17-19 years old), and a few more terms.
Could the native English speakers answer me if there are the English words to match their Russian equivalents I tried to define in English?
Also, about the two words I mentioned in the beginning of the post:
Are they really in use?
In your culture, what would be the maximal age difference between the persons to say that they are agemates?