Why Cheshvan & Kislev?
The Tur (O.Ch. 428) writes
,”Tishrei is always a full month (30days) and Teves is always a missing
(short) month (29days)
The months alternate one month
is full and the following is short.
The months of Cheshvan &
Kislev are exceptions. Some years both months are full.(שנה שלמה ). Some years both
months are short ( חסרה ) and some years one is
full and the other is short (כסדרה)“
The reason for this is to
equalize the months. A lunar cycle is
29 days+12hours+ 793 Chalokim
(Aprox. ¾ hr.)
The Levush explains why did
Chazal pick Cheshvan & Kislev
to change the system of
alternating full and short months.and
not any other month.
“The first opportunity we have
to add or subtract from the month is on the month of Cheshvan.
We can’t do it on Nissan &
Iyar because the 50th day of Sefirah needs to be on the 6th
of Sivan. (by adding or subtracting a day
we will have it on the 5th or the 7th )
From Shavuos till Yom Kippur we
need to have 3x 40 days.
to commemorate the 3x 40 days
from Moshe Rabeinu standing
on the mountain (Shavuos) and
bringing down the Luchos on
Yom Kippur.
Chodesh
Tishrei is the king of the Chodoshim and the Month
with
Yomim Tovim (ירח האתנים
) we can’t make it a חסר .
Therefore the first opportune
time is on the month of Cheshvan.
