[Avodah] FW: More on daveneing late Shovuos

[SBA]

..The Klausenberger Rebbe, zt'l, in Divrei Yatziv (O.C., No. 226) writes
that the reason we are stringent is not because it does not complete the 49
days of the omer, but rather because it appears as if we have not completed
the full 49 days of the omer! He adduces this reading also from the wording
of the Shulchan Aruch HaRav (the first Rebbe of Chabad).
It is interesting to note that Rav Chaim Berlin (the son of the Netziv and
the Chief Rabbi of Moscow from 1865), in Koveitz Shaarei Torah, Volume 8
(9:68), has an entirely different reading of this Taz. He writes that the
Taz is not dealing with any special aspect of Shavuos. Rather, he explains,
just as during all other days of the omer the counting must be perfect,
without the internal contradiction of having to count it on a different day,
the same is true with the 49th day: the omer may not be counted on a day the
latter part of which is shared with Shavuos.
The Tzitz Eliezer (Volume 13, No. 59), however, rejects Rav Chaim Berlin's
interesting rereading of the Taz and maintains that the idea of "b'etzem
ha'yom ha'zeh" makes this halachah unique to Shavuos.
Another issue relates to the second day of Shavuos. There is an enactment to
keep two days of yom tov in Chutz LaAretz (on account of sefeika d'yoma-an
uncertainty in the day that rosh chodesh was declared). Can we daven early
on the second night (Friday night), or do we have to wait until the time the
stars come, just as we do on the first night of Shavuos?...
http://matzav.com/shavuos-counting-temimos/