The Luckiest Day of 2026 Is Also Its Worst

On September 30 the Fukui Shimbun published its calendar of lucky days for October and led with the following day: October 1, 2026, where a Heaven's Pardon day fell on an Ichiryu Manbai day. Over the next two days the same framing ran at Mynavi, HugKum and Yahoo Japan, with one of them calling it one of the year's top-class super-lucky days. The Fukui Shimbun's own line was modest enough:

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Tomorrow, 1 October, is a lucky day worth watching: a Heaven's Pardon day and an Ichiryu Manbai day fall together.

A Heaven's Pardon day — tenshanichi, in Japanese — is the highest-ranked single day in the Japanese calendar notes, the layer of annotations that sits beneath the date itself. An Ichiryu Manbai day is the one where a single grain is said to return ten thousand. This site does not publish either of them, and before saying why, it is worth saying that the part of this which can be checked checks out.

The rule behind Heaven's Pardon days, and it holds

Heaven's Pardon day has a rule, stated in one line and settled by the sexagenary cycle: in spring it is the Yang Earth Tiger day, in summer Yang Wood Horse, in autumn Yang Earth Monkey, in winter Yang Wood Rat — with the seasons taken from the solar terms, so spring begins at the Start of Spring rather than on any civil date. That is the kind of claim we can run rather than repeat. October 1, 2026, is the Yang Earth Monkey day of the Rooster solar month, which White Dew opened, which is autumn. It is a Heaven's Pardon day, and the reports have it right.

We then ran the rule across the whole of 2026 and got six days: March 5, May 4, May 20, July 19, October 1 and December 16. Those are, date for date, the six that the Japanese almanac sites publish — no misses and nothing extra. That is worth more to us than the day itself. It means the rule as we have written it and the rule as Japan actually keeps it are the same rule, and when two independent implementations of a traditional calculation agree on all six cases, the calculation is being transmitted rather than improvised.

And the same calendar calls it the worst day of the week

Here is the part the headlines leave out. Open any of those Japanese calendar pages at October 1 and the line for the rokuyo, Japan's six-day cycle, reads Butsumetsu — the least favorable of the cycle of six, the one wedding halls discount. Mynavi's October page, published on the 2nd, prints both on the same row: Butsumetsu for the rokuyo, and beside it Heaven's Pardon day, Ichiryu Manbai day and Kamiyoshi day (a day for shrine rites).

The rokuyo is not a layer a Chinese Tong Shu prints — in its modern form it is a Japanese fixture — but its rule is arithmetic on the lunar date, so we can derive it from what this site already computes. Take the lunar month plus the lunar day and divide by six: the remainder names the day, counting Taian, Shakko, Sensho, Tomobiki, Senbu, Butsumetsu. Our lunar code puts October 1, 2026, at the 21st day of the eighth lunar month. Eight plus twenty-one is twenty-nine, which leaves five, which is Butsumetsu. The published calendars and our arithmetic agree.

So the superlative and its contradiction sit in the same table, derived by two different rules from the same date, and neither is a mistake. A reader who takes "luckiest day of the year" as a fact about October 1 has to do something with the Butsumetsu printed an inch away, and there is nothing to do with it except notice that the calendar was never speaking with one voice.

What our own almanac says about October 1

A third answer, for completeness, and it is not kinder. Run the date through this site's own almanac and the day officer is Close — the twelfth and last, which the classical mnemonic puts in its bottom grade, not to be used. Its day god is the White Tiger, which makes it a Black Path day rather than a Yellow Path one. The day pillar is Yang Earth Monkey, Earth of the Post Road by sound element (Na Yin), the lunar mansion is Legs (Wood Wolf), and it clashes with the Tiger. Six of its twelve hours are favorable, which is simply the ordinary half.

We are not offering that as a correction. It is a fourth tradition arriving at a fourth verdict, and the honest description of the situation is that Heaven's Pardon days, the rokuyo and the day officers are three different selections that were never reconciled with one another and are not reconcilable now. What each of them can tell you is what it computed and from which rule. What none of them can tell you is which of the three to believe, because that question has no rule attached to it at all.

Ten minutes of clock moves the rest of the month

One more thing fell out of the checking, and it is the part we would most want a reader to keep. Our rokuyo matches the published Japanese lists exactly for 1 through October 9 — Butsumetsu on the 1st and 7th, Taian on the 2nd and 8th, Shakko on the 3rd and 9th. From the 10th onward every single day is off by one. We have Taian on the 12th, 18th, 24th and 30th; they have it on the 13th, 19th, 25th and 31st.

Neither list is wrong. October's new moon falls at 15:50 UT on the 10th. That is 23:50 on the 10th in Beijing and 00:50 on the 11th in Tokyo. Our lunar module counts months in Beijing time, so the first day of the ninth lunar month is the 10th; the Japanese calendar counts them in Japan time, so it is the 11th. Every lunar date for the rest of the month shifts by a day, and because the rokuyo is arithmetic on the lunar date, every rokuyo day shifts with it. Ten minutes of clock and one hour of longitude, and the dates people are planning a month around move.

This is why the site marks that condition rather than quietly picking a side. A reading that depends on a ten-minute margin should say so, in the same way a Flying Star chart near a 24-mountain boundary should say so instead of committing to a chart it cannot justify. The honest version of "October 1 is a Heaven's Pardon day" is that it is one on both meridians; the honest version of "the 13th is Taian" is that it is in Tokyo and is not in Beijing.

Our honest read

The Fukui Shimbun did nothing wrong here. It published a calendar, the calendar's arithmetic is correct, and plenty of people find it useful to have a date in the diary that the tradition marks out — there is no harm in signing a lease or opening an account on a day you have reason to remember. We would not tell anybody to stop.

What we would not do is carry the ranking across. The derivable claim is narrow and it is genuinely transmitted: October 1, 2026, is a Yang Earth Monkey day in autumn, therefore a Heaven's Pardon day, and six implementations of that rule land on the same six days of the year. Everything above that — best day of the year, super money day, the doubling that makes it stronger — is an ordering that no text supplies and no code can produce. The gap between those two kinds of sentence is the only thing this site is really trying to teach, and October 1, 2026, is an unusually clean specimen: the calendar that calls it the best day of the year also calls it the worst day of the week, and it is right both times.