It is often very hard to predict how long a certain technological development will take. The moon landing happened sooner than most people had expected, but fusion energy still eludes us after half a century of anticipation. The difficulty in forecasting the timing lies partly in the possibility of unexpected technical obstacles and partly in the fact that the rate of progress depends on levels of funding, which in turn depends on hard-to-predict economic and political factors. Therefore, while one can in many cases give good grounds for thinking that a technology will eventually be developed, one can usually only make informed guesses about how long it will take.
Later in the anime, the Super Saiyan 2 form is used by Goku in his first fight with Goku Black . Super Saiyan 2 Goku was strong enough to deal some damage and leave Goku Black in pain. Goku returns to use this form again during his brief fight against Zamasu in Universe 10 . While the battle is even for a while, Goku soon manages to overpower Zamasu. Future Trunks returns to use this form briefly during his training with Vegeta, he also transforms into Super Saiyan Third Grade from his Super Saiyan 2 form in order to trick Vegeta and hit him, but to no avail.
Originally, the game took place in early to mid-January. For Super Bowl I there was only one round of playoffs: the pre-merger NFL and AFL Championship Games. The addition of two playoff rounds (first in 1967 and then in 1978), an increase in regular season games from 14 to 16 (1978), and the establishment of one bye-week per team (1990) have caused the Super Bowl to be played later. Partially offsetting these season-lengthening effects, simultaneous with the addition of two regular season games in 1978, the season was started earlier. Prior to 1978 the season started as late as September 21. Now, since Labor Day is always the first Monday of September, September 13 is the latest possible date for the first full Sunday set of games (Since 2002, the regular season has started with the Kickoff Game on the Thursday after Labor Day).