The Essene Calendar begins the year at the Spring Solstice.  According to Scripture (Exodus 12:2) the first month occurs in the Spring.
The calendar contains twelve 30-day months.  Each soltice is set apart and is not part of a month. 12 times 30 days equals 360 days
plus 4 days of solstice equals 364 days. By beginning each year at the Spring Solstice, the calendar is self-correcting.
ESSENE CALENDAR GREGORIAN CALENDAR
RED INDICATES DATES OF NOTE RED INDICATES DATES OF NOTE
NISSAN  MAR / APR
S M T W T F S S M T W T F S
Spring 1 2 20 21 22
3 4 5 6 7 8 9 23 24 25 26 27 28 29
10 11 12 13 14 15 16 30 31 APR 1 2 3 4 5
17 18 19 20 21 22 23 6 7 8 9 10 11 12
25 26 26 27 28 29 30 13 14 15 16 17 18 19
IYAR  APR / MAY
S M T W T F S S M T W T F S
1 2 3 4 5 6 7 20 21 22 23 24 25 26
8 9 10 11 12 13 14 27 28 29 30 MAY 1 2 3
15 16 17 18 19 20 21 4 5 6 7 8 9 10
22 23 24 25 26 27 28 11 12 13 14 15 16 17
29 30 18 19
SIVAN MAY / JUNE
S M T W T F S S M T W T F S
1 2 3 4 5 20 21 22 23 24
6 7 8 9 10 11 12 25 26 27 28 29 30 31
13 14 15 16 17 18 19 JUNE 1 2 3 4 5 6 7
20 21 22 23 24 25 26 8 9 10 11 12 13 14
27 28 29 30 15 16 17 18
TAMMUZ JUNE / JULY
S M T W T F S S M T W T F S
Summer 1 2 19 20 21
3 4 5 6 7 8 9 22 23 24 25 26 27 28
10 11 12 13 14 15 16 29 30 JULY 1 2 3 4 5
17 18 19 20 21 22 23 6 7 8 9 10 11 12
24 25 26 27 28 29 30 13 14 15 16 17 18 19
AV JULY / AUG
S M T W T F S S M T W T F S
1 2 3 4 5 6 7 20 21 22 23 24 25 26
8 9 10 11 12 13 14 27 28 29 30 31 AUG 1 2
15 16 17 18 19 20 21 3 4 5 6 7 8 9
22 23 24 25 26 27 28 10 11 12 13 14 15 16
29 30 17 18
ELUL AUG / SEPT
S M T W T F S S M T W T F S
1 2 3 4 5 19 20 21 22 23
6 7 8 9 10 11 12 24 25 26 27 28 29 30
13 14 15 16 17 18 19 31 SEPT 1 2 3 4 5 6
20 21 22 23 24 25 26 7 8 9 10 11 12 13
27 28 29 30 14 15 16 17
TISHRI SEPT / OCT
S M T W T F S S M T W T F S
Fall 1 2 18 19 20
3 4 5 6 7 8 9 21 22 23 24 25 26 27
10 11 12 13 14 15 16 28 29 30 OCT 1 2 3 4
17 18 19 20 21 22 23 5 6 7 8 9 10 11
24 25 26 27 28 29 30 12 13 14 15 16 17 18
HESHVAN OCT / NOV
S M T W T F S S M T W T F S
1 2 3 4 5 6 7 19 20 21 22 23 24 25
8 9 10 11 12 13 14 26 27 28 29 30 31 NOV 1
15 16 17 18 19 20 21 2 3 4 5 6 7 8
22 23 24 25 26 27 28 9 10 11 12 13 14 15
29 30 16 17
KISLEV NOV / DEC
S M T W T F S S M T W T F S
1 2 3 4 5 18 19 20 21 22
6 7 8 9 10 11 12 23 24 25 26 27 28 29
13 14 15 16 17 18 19 30 DEC 1 2 3 4 5 6
20 21 22 23 24 25 26 7 8 9 10 11 12 13
27 28 29 30 14 15 16 17
TEVETH DEC / JAN
S M T W T F S S M T W T F S
Winter 1 2 18 19 20
3 4 5 6 7 8 9 21 22 23 24 25 26 27
10 11 12 13 14 15 16 28 29 30 31 JAN 1 2 3
17 18 19 20 21 22 23 4 5 6 7 8 9 10
24 25 26 27 28 29 30 11 12 13 14 15 16 17
SHEBAT JAN / FEB
S M T W T F S S M T W T F S
1 2 3 4 5 6 7 18 19 20 21 22 23 24
8 9 10 11 12 13 14 25 26 27 28 29 30 31
15 16 17 18 19 20 21 FEB 1 2 3 4 5 6 7
22 23 24 25 26 27 28 8 9 10 11 12 13 14
29 30 15 16
ADAR FEB / MAR
S M T W T F S S M T W T F S
1 2 3 4 5 17 18 19 20 21
6 7 8 9 10 11 12 22 23 24 25 26 27 28
13 14 15 16 17 18 19 MAR 1 2 3 4 5 6 7
20 21 22 23 24 25 26 8 9 10 11 12 13 14
27 28 29 30 15 16 17 18
Nisan 1 Correct beginning of the year (Exodus 12:1-6)
Nisan 10 Passover Lamb chosen (Exodus 12:3)
Nisan 14 Passover begins at Sundown (Leviticus 23:5)
Nisan 15 The Feast of Unleavened Bread (Leviticus 23:6)
Nisan 17 The first Sunday after Passover is the Day of Firstfruits and also Ressurection Sunday!
It begins the fifty day count for Pentecost  (Leviticus 23:11)
Sivan 6 Shavuot - Pentecost (Leviticus 23:16)
Tammuz 17 Traditional anniversary of destruction of the walls of Jerusalem (twice)
Av 9 Traditional anniversary of destruction of the Temple (twice)
Tishri 1 Rosh HaShanah - Feast of Trumpets (Leviticus 23:23)
Tishri 10 Yom Kippur - Day of Atonement (Leviticus 23:26)
Tishri 15 Sukkot - Feast of Booths, Feast of Harvest (Leviticus 23:33)
Kislev 25 Chanukah - Festival of Lights (see History of Maccabean Revolt)
Adar 14 & 15 Purim - see Book of Esther