we see from tosafot that we can apply the times of tefila to zman kerias shema, the only problem was the trei kuli, so why doesnt tosfot answer that we pasken like the chachomim of r' yehuda that hold ad haerev, which most poskim hold is skiat hachama, and that would be the same time as the ri that says mishekidesh hayom which is the begining of bein hashemashot, aka shkiat hachama
Marcus Abisror, Long Branch
Shalom Marcus,
I'm not sure I understand your question. What Tosfos is trying to explain is how do we recite Ma'ariv after Plag ha'Minchah which is more than an hour before Sheki'ah! Your solution is valid only if the question was how do recite Ma'ariv right after, or right at, the time of Sheki'ah time.
If I am missing something, please explain your question more.
Kol Tuv,
Aharon Steiner