Since the conjunction of sun and moon was on the 13th I think Passover comes out on the 27 of March. That is Friday night, the night of the 26. That would be like R. Elazar in Sanhedrin page 10 that the new moon does not depend on the court on earth. Rather if the court on earth sanctifies the new moon at the right time then fine,-but if not, then the heavenly court does so anyway.
Everyone seems to think that the new moon depends on the lower court according to all opinions, but you certainly do not see that in Sanhedrin. Just the opposite. The later opinions of Rav Ashi and Rava go with the idea of R. Elazar. And even if the new moon would depend on the lower court, there has not been a lower court to sanctify it since the middle of the Talmudic period when the authentic semicha died out.
And the idea of Hillel II sanctifying the later new moons is a myth never mentioned anywhere in the Gemara.
Since semicha disappeared during the time of the amoraim [Talmudic sages] the dates were in doubt. Only a court with authentic ordination can sanctify the new moon. During the time of the geonim at some point they accepted the calendar of Meton. But there is no indication that Hillel II sanctified it.
letters from the early geonim have the dates of their writing to not be in accord with the present calendar, but sometime around the time of saadia gaon you see the present day calendar being accepted. but at least we knw the present day calendar is not from the talmud.
