# "Hanukkah 8th day/Tevet 3/New Years Day" triple coincidences - What makes them so Rare?

I very recently became aware that Hanukkah 8th day sometimes (but rarely) falls on Tevet 3. What causes this to happen? At the same time, I also noticed that when Hanukkah 8th day/Tevet 3 happen together, this sometimes occurs in conjunction with the Gregorian New Year's Day (January 1). Additionally, when such triple coincidences occur, they always occur on the first day of the week (i.e. Sunday). One such "triple occurrence" happened most recently in 2017 (5777 Hebrew year). However, another one also occurred in 1797 (5557 Hebrew year), and yet another will apparently occur 150 years from now in the Gregorian year 2169 (5929 Hebrew year). So I now have a couple of related questions....

1) Can someone tell me the calendar conditions that cause Hanukkah 8th day to fall on Tevet 3?

2) Can anyone possibly extrapolate from that to tell me how frequently it might occur as a "triple event" with the Gregorian New Years Day? (I can only find two occurrences since the calendar shift from Julian to Gregorian happened in 1582). Thank you for all of your help.

BONUS QUESTION: Hebcal seems to indicate that another triple occurrence also happened in the Gregorian year 1550. I highly doubt that this is correct because this date is prior to adoption of the Gregorian calendar when the all important "11 day date shift" occurred - that would make the triple occurrence in Gregorian year 1550 theoretically impossible. So, it doesn't seem to be correct. Is it possible that Hebcal is not calculating correctly? Can someone check this out? Does anyone know how reliable Hebcal is?

Edit/Update: I became more curious, so I manually checked the entire date range from Gregorian years 1797 to 3797 for any "Hanukkah 8th day/Tevet 3/January 1" triple occurrences. This is what I found:

I found a mere eight triple occurrences of "Hanukkah 8th day/Tevet 3/January 1" over the entire span of 2000 years - 1797, 2017, 2169, 2275, 2389, 2609, 3486, and 3706. These 8 triple occurrences seemed to happen LESS frequently in future years according to Hebcal with a large gap between 2609 and 3486. The dates in Bold all occurred on Sunday. The dates in Italics all occurred on Friday. Furthermore, several of the dates appear to be equally spaced by 220 years (except for 2017 to 2169 and 2609 to 3486). I did observe that the Hebrew dates do seem to be shifting gradually (slightly) relative to the Gregorian solar calendar. I do not know the reason for this. I expected them to be continuous and relatively stable and in-sync. I also observed that starting with the Gregorian year 3032, Hanukkah/Kislev 25 begins to fall on January 1 (after that such "New Years Day/Kislev 25" occurrences happen regularly).

I suppose I may have missed one or two occurrences, but probably not many. I wanted to post this update for any who might be interested in the date patterns. Thank you for your answers.

• The "missing" days to correct the calendar from Julian to Gregorian were added in different years in different countries, and the number of days needed varied according to this date. It is therefore critical that Hebcal is defined re the location. Sep 14, 2019 at 9:41
• @Epicenter Yes, I realize that, but Hebcal seems to indicate a date (1752 C.E.) alluding to the Gregorian shift. The shift should have made it impossible for Hanukkah 8th/Tevet3/New Years to coincide. That is why I wonder about 1550 C.E. - why is that one date so questionable? Or, are more possibly inaccurate? I was hoping that someone might check out 1550 and know what was the reason. But, thank you for response. Sep 14, 2019 at 10:36
• Welcome to MiYodeya and thanks for this first question. Since MY is different from other sites you might be used to, see here for a guide which might help understand the site. Great to have you learn with us! Sep 14, 2019 at 16:46
• If it helps narrow things down, this occurs only on year 9 of the 19 year cycle and that year has to be chasera (deficient). I state this because year 8 produces the latest Pesach start date in the cycle, so that would make Chanukah the latest possible. And a chasera is the only time last day of Chanukah would be on 3 Tevet. See if you can use these parameters in Hebcal or some other program. AT least, you have a rather narrow criteria set.
– DanF
Sep 15, 2019 at 23:06
• This is why it drifts over time judaism.stackexchange.com/a/98187/759 Sep 16, 2019 at 19:25

Answer to 1) - 3 Tevet is the latest date that 8th day Chanukah can occur. This means that both Chehsvan and Kislev are Chaser (deficient - having both 29 days), making the year itself a Chaser. I have to check the kevi'ot chart to see what days of the week Rosh Hashanna occurs for such keviyot.

As for other criteria, either Jan. 1 or 2 are the latest dates for the last day of Chanukah. This would occur only in year 9 of the 19 year cycle.

• I don't think Teves has to be chaser... Sep 15, 2019 at 23:16
• I corrected the error. I meant Chehsvan and Kislev.
– DanF
Sep 15, 2019 at 23:25
• I don't think cheshvan has to be chaser either...? Chanukah is always the 25 of Kislev, regardless of how many days were in cheshvan Sep 15, 2019 at 23:39
• @robev If marcheshvan has 30 days then kislev must also have 30 days Sep 16, 2019 at 3:07
• @DanF Thank you. If I apply statistics then between the two answers it suggests 1/19 which is roughly 5% (falling on Jan 1) and roughly 25% (falling on Tevet 3), so .05 x .25 would be slightly more than 1/100 years. But, I checked each year manually at Hebcal and only found 3 times between 1752 and 2169 which is 3 times/417 years = about 1 time/140 years. It is close - maybe (maybe for small sample set). Do you concur with the second answer that Hanukkah 8th day occurs about once every 4 years? And so both conditions must apply? Do you also doubt the Hebcal 1550 C.E. result? Sep 16, 2019 at 7:36

On average the last day of Chanukah is on 3 Tevet about once every 4 years. This has to do with the month of Kislev having 29 days. (happened in 2000, 2004, 2007, 2012, 2016. Will happen in 2020, 2023, 2029, 2032, 2036, 2040, 2043, 2047....)

Regarding how often 3 Tevet is on January 1 and also the last day of Chanukah it never happened in the 20th century. In 1914, 1933, 1952, 1998 the third of Tevet was on January 1, however it was the day after Chanukah.

The last day of Chanukah comes out as late as January 3. This occured in 1949, 1968, 1987, and will next occur in 2044.

• So, I gather that Hanukkah 8th day occurs on Tevet 3 only in deficient years? Since I am only interested in when it falls on Jan 1 - How often does that occur? Do you know roughly what % years are deficient and What % years have Hanukkah 8 falls in January? I want to compare the answers. Sep 16, 2019 at 7:47