The Hebrew Calendar is Lunar based.  The New Moon notes the first day of the month.
HEBREW CALENDAR GREGORIAN CALENDAR
RED INDICATES DATES OF NOTE BLUE INDICATES NEW MOON
TISHRI - 5770 SEPT/OCT - 2009
S M T W T F S S M T W T F S
1 18 19
2 3 4 5 6 7 8 20 21 22 23 24 25 26
9 10 11 12 13 14 15 27 28 29 30 OCT 1 2 3
16 17 18 19 20 21 22 4 5 6 7 8 9 10
23 24 25 26 27 28 29 11 12 13 14 15 16 17
30 18
HESHVAN - 5770 OCT/NOV - 2009
S M T W T F S S M T W T F S
1 2 3 4 5 6 19 20 21 22 23 24
7 8 9 10 11 12 13 25 26 27 28 29 30 31
14 15 16 17 18 19 20 NOV 1 2 3 4 5 6 7
21 22 23 24 25 26 27 8 9 10 11 12 13 14
28 29 30 15 16 17
KISLEV - 5770 NOV/DEC - 2009
S M T W T F S S M T W T F S
1 2 3 4 18 19 20 21
5 6 7 8 9 10 11 22 23 24 25 26 27 28
12 13 14 15 16 17 18 29 30 DEC 1 2 3 4 5
19 20 21 22 23 24 25 6 7 8 9 10 11 12
26 27 28 29 30 13 14 15 16 17
TEVETH - 5770 DEC/JAN - 2009
S M T W T F S S M T W T F S
1 2 18 19
3 4 5 6 7 8 9 20 21 22 23 24 25 26
10 11 12 13 14 15 16 27 28 29 30 31 JAN 1 2
17 18 19 20 21 22 23 3 4 5 6 7 8 9
24 25 26 27 28 29 10 11 12 13 14 15
SHEBAT - 5770 JAN/FEB - 2010
S M T W T F S S M T W T F S
1 16
2 3 4 5 6 7 8 17 18 19 20 21 22 23
9 10 11 12 13 14 15 24 25 26 27 28 29 30
16 17 18 19 20 21 22 31 FEB 1 2 3 4 5 6
23 24 25 26 27 28 29 7 8 9 10 11 12 13
30 14
ADAR - 5770 FEB/MAR - 2010
S M T W T F S S M T W T F S
1 2 3 4 5 6 15 16 17 18 19 20
7 8 9 10 11 12 13 21 22 23 24 25 26 27
14[1] 15 16 17 18 19 20 28 MAR 1 2 3 4 5 6
21 22 23 24 25 1 7 8 9 10 11 12 13
28 29 14 15
NISAN - 5770 MAR/APR - 2010
S M T W T F S S M T W T F S
1[2] 2 3 4 5 16 17 18 19 20
6 7 8 9 10 11 12 21 22 23 24 25 26 27
13 14 15 16 17 18 19 28 29 30 31 APR 1 2 3
20 21 22 23 24 25 26 4 5 6 7 8 9 10
27 28 29 30 11 12 13 14
IYAR - 5770 APR/MAY - 2010
S M T W T F S S M T W T F S
1 2 3 15 16 17
4 5 6 7 8 9 10 18 19 20 21 22 23 24
11 12 13 14 15 16 17 25 26 27 28 29 30 MAY 1
18 19 20 21 22 23 24 2 3 4 5 6 7 8
25 26 27 28 29 9 10 11 12 13
SIVAN - 5770 MAY/JUNE - 2010
S M T W T F S S M T W T F S
1 2 14 15
3 4 5 6 7 8 9 16 17 18 19 20 21 22
10 11 12 13 14 15 16 23 24 25 26 27 28 29
17 18 19 20 21 22 23 30 31 JUNE 1 2 3 4 5
24 25 26 27 28 29 30 6 7 8 9 10 11 12
TAMMUZ - 5770 JUNE/JULY - 2010
S M T W T F S S M T W T F S
1 2 3 4 5 6 7 13 14 15 16 17 18 19
8 9 10 11 12 13 14 20 21 22 23 24 25 26
15 16 17 18 19 20 21 27 28 29 30 JULY 1 2 3
22 23 24 25 26 27 28 4 5 6 7 8 9 10
29 11
AV - 5770 JULY/AUG - 2010
S M T W T F S S M T W T F S
1 2 3 4 5 6 12 13 14 15 16 17
7 8 9 10 11 12 13 18 19 20 21 22 23 24
14 15 16 17 18 19 20 25 26 27 28 29 30 31
21 22 23 24 25 26 27 AUG 1 2 3 4 5 6 7
28 29 30 8 9 10
ELUL - 5770 AUG/SEPT - 2010
S M T W T F S S M T W T F S
1 2 3 4 11 12 13 14
5 6 7 8 9 10 11 15 16 17 18 19 20 21
12 13 14 15 16 17 18 22 23 24 25 26 27 28
19 20 21 22 23 24 25 29 30 31 SEPT 1 2 3 4
26 27 28 29 5 6 7 8
Tishri 1 Rosh HaShanah - Beginning of Secular Year (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
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)
The first Sunday after Passover begins the fifty day count
for Pentecost  (Leviticus 23:11)
Sivan 8 Shavuot - Pentecost (Leviticus 23:16)
Tammuz 17 Anniversary of destruction of the walls of Jerusalem (twice)
Av 9 Anniversary of destruction of the Temple (twice)

[1]
Ronald Taylor:
2,520 "Sacred" Years from Haman's Decree
[2]
Ronald Taylor:
Nisan 1 is early.  The grain may not be "abib".