<P> Throughout the first two seasons, episodes opened with title cards showing the season / month and year (example: Late Spring, 1977 or June 1977). These, however, were largely abandoned after season 2, with few subsequent episodes using them . However, they were used again in the final episode, showing "December 31, 1979 10: 45 a.m." From the premiere onward, the episode's year could be determined by the registration tags on Eric's Vista Cruiser at the end of the opening and closing credits . The final episode's closing credits showed an "80" year tag . </P> <P> The show was set in May 1976 in the August 23, 1998 premiere . After 12 episodes, the series transitioned to 1977 . The 23rd episode, "Grandma's Dead", was also set in 1976, because it was supposed to be the season finale of season 1 . The show remained in 1977 for the next two seasons . Near the end of the third season, the series transitioned to 1978 until early in the sixth season . The remaining episodes took place in 1979, and the series finale abruptly ends during a New Year's Eve party as the characters reach "one" during a countdown to January 1, 1980 . </P> <P> The show's unexpected longevity (it was the only series to debut on Fox in 1998 to survive cancellation) combined with the first season jump to 1977 necessitated a slow - down of the series' timeline . Over time, this proved problematic from a narrative standpoint, as nearly every year featured a Thanksgiving and / or Christmas episode, and the teen - aged actors playing high - school student characters all aged into their mid-20s by the time their characters graduated from high school after five seasons (except Mila Kunis, who was not quite 20). As the series timeline sped up and slowed down with more rapidity near the series' climax, the timeline necessitated that several major events depicted as having occurred months apart would have in fact happened within weeks or even days of one another . </P> <P> The timeline issues experienced on the show were not unprecedented, as other period - specific TV series have had similar issues . Most notably, M * A * S * H aired for 11 seasons despite the Korean War only lasting three years . Additionally, many TV series over the years that take place in the present time have characters age faster than normal while other characters age naturally . </P>

How old was the cast of that 70's show when it first aired
find me the text answering this question