Expected New Moons and Appointed Times for 2018

Listed below are the computations for 2018 for the expected dates of New Moon visibility from Israel. The possible projected dates for the Appointed Times for 2018 are given in a second table below the New Moons table.

PLEASE NOTE: The "Date of Visibility" column dates are the dates on which the New Moon is expected to be seen--beginning at sunset of the listed day. All dates listed are to be reckoned from sunset of listed day and date through the next day at sunset in the following New Moon table.

**2018/2019 New Moon Data**
New Moon	Date of Visibility	Sunset	Moon Set	Lag Time	% of Illum.	Moon Alt.	Sun Alt.	VN	Sighted?	Length
11th	Thursday, January 18, 2018	5:00	6:18	78 min.	2.12 %	13.7	-15.7	170.0	Yes	30
12th	Saturday, February 17, 2018	5:27	6:58	91 min.	3.15 %	17.3	-19.3	216.1	Yes	29
1st	Sunday, March 18, 2018	5:49	6:46	57 min.	1.52 %	10.8	-12.1	128.2	Yes	30
2nd	Tuesday, April 17, 2018	7:09	8:39	90 min.	3.42 %	17.3	-18.0	216.0	Yes	29
3rd	Wednesday, May 16, 2018	7:29	8:35	66 min.	2.16 %	11.9	-12.2	147.4	Yes	30
4th	Friday, June 15, 2018*	7:46	9:30	104 min.	5.28 %	19.3	-17.6	259.0	Yes	29
5th	Saturday, July 14, 2018	7:46	9:04	78 min.	3.83 %.	14.7	-14.0	195.4	Yes	29
6th	Sunday, August 12, 2018	7:26	8:26	60 min.	2.48 %	11.4	-11.8	146.1	Yes	29
7th	Monday, September 10, 2018*	6:52	7:38	46 min.	1:32 %	8.75	-9.77	105.1	9/11	29
8th	Wednesday, October 10, 2018	6:13	7:24	71 min.	2.94 %	13.3	-15.1	176.0	Yes	29
9th	Thursday, November 8, 2018*	4:44	5:35	51 min.	1.16 %	9.11	-10.5	108.8	11/9	30
10th	Saturday, December 8th, 2018	4:35	5:41	66 min.	1.71 %	11.1	-13.0	140.2	Yes	30
11th	Monday, January 7, 2019	4:51	6:07	76 min.	2.19 %	13.1	-15.3	166.8	Yes	30
12th	Wednesday, February 6, 2019	5:17	6:43	86 min	2.82 %	15.6	-17.8	198.2		29 or 30
1st/13th	Thursday, March 7, 2019*	5:41	6:25	44 min.	1.05 %	8.14	-9.5	96.84		29 or 30

* Friday, June 15, 2018 - The moon may possibly be visible one evening earlier, but most likely not. Here are the stats for that date: On Thursday evening (June 14), we expect a 7:46 pm sunset & 8:27 pm moon set (therefore, a lag time of 41 minutes), a 1.22% of illumination, with a lunar altitude at sunset of 7.15 degrees and a solar altitude of -7.51 at moonset. VN = 88.69 **UPDATE - Not visible June 14th, but was sighted June 15th as expected.

* Monday, September 10, 2018 - The moon may not be visible until the next evening. Here are the stats for the next evening: Tuesday evening, September 11th, we expect a 6:51 pm sunset & 8:16 pm moon set (therefore, a lag time of 85 minutes), a 5.18% of illumination, with a lunar altitude at sunset of 16.7 degrees and a solar altitude of -17.8. VN = 238.9 **UPDATE - Not visible September 10, but was sighted September 11.

* Thursday, November 8, 2018 - The moon may not be visible until the next evening. Here are the stats for the next evening: Friday evening, November 9th, we expect a 4:43 pm sunset & 6:17 pm moon set (therefore, a lag time of 94 minutes), a 4.24% of illumination, with a lunar altitude at sunset of 16.3 degrees and a solar altitude of at -19.4 moonset. VN = 232.5

* Thursday, March 7, 2019 - The moon may not be visible until the next evening. Here are the stats for the next evening: Friday evening, March 8th, we expect a 5:42 pm sunset & 7:20 pm moon set (therefore, a lag time of 98 minutes), a 3.82% of illumination, with a lunar altitude at sunset of 19.0 degrees and a solar altitude of -20.8 at moonset. VN = 241.0

**2018 Appointed Times (March 18th/19th New Year)**
Event	begins sunset of	ends sunset of
Passover (Lord's Supper)	Saturday, March 31	Sunday, April 1
Feast of Unleavens (1st day)	Sunday, April 1	Monday, April 2
Elevation Sheaf Day (aka "wave sheaf")	Saturday, April 7	Sunday, April 8
Feast of Unleavens (7th day)	Saturday, April 7	Sunday, April 8
Pentecost	Saturday, May 26	Sunday, May 27
Day of Shouting (aka "Trumpets")	Tuesday, September 11	Wednesday, September 12
Day of Atonement	Thursday, September 20	Friday, September 21
Feast of Tabernacles (1st day)	Tuesday, September 25	Wednesday, September 26
8th Day Assembly	Tuesday, October 2	Wednesday, October 3

Understanding the Calculations

Visibility Number (VN) is the difference between the sun and moon setting times plus 27 times the illuminated percent of the moon plus 5.5 times the altitude of the moon at sunset minus 5 times the altitude of the sun at moonset, all divided by 1.7.

If the VN is:

* less than 88 then the New Moon will not be seen
* between 88 and 100, it will probably not be seen
* between 100 and 112, it will probably be seen
* anything greater than 112, it will be seen in reasonable conditions.

EXAMPLE: The sun will set in Jerusalem at 6:37. The moon will set at 7:36. This is a 59 minute lag time (lag time = the time between sunset and moonset) -- plenty of time for the sky to darken enough after sunset for the moon to be sighted. 2.39% of the lunar surface will be illuminated. And the moon's altitude at sunset will be 11.4 degrees. The sun's altitude at moonset will be -12.6 degrees.

So using the calculations, we have 59 [lag time] + (27 x 2.39 = 64.53) [27 times illuminated percent] + (5.5 x 11.4 = 62.7) [5.5 times lunar altitude] - (5 x -12.6 = -63) [5 times sun's altitude] divided by 1.7 = 146.6

As seen above, anything over 112 should be visible (the higher the number, the greater the visibility), and we have a VN of 146.6 -- hence, New Moon!

Email: Brian Hoeck

©2018 Truth On The Web Ministries: All the articles originated by Kenneth Hoeck and/or Brian Hoeck may be freely distributed or mirrored as long as presented in their entirety (including this statement), attributed to Truth on The Web, and proper author credit given.

Back to CALENDAR CHRONICLES