Keep only Saturday or Sunday Taian days for a wedding, and the count almost halves from one year to the next. Taian itself appears about 60 times a year; whether those days land on a weekend depends on lunar month resets. Using the same engine as the Rokuyō calendar, we counted every day in 2025–2027 and listed every weekend Taian. Rokuyo is calendar folklore with no scientific basis.

The formula: Taian is remainder 0 of (lunar month + day) ÷ 6

A day is Taian when the lunar month number plus the lunar day, divided by 6, leaves remainder 0. When the lunar month rolls over, the day returns to 1 and the six-day cycle restarts, so Taian slides against the seven-day week. Counting only Saturday and Sunday Taian:

YearAll TaianSaturday TaianSunday TaianWeekend total
20256091120
202661111021
2027607411

There are 21 weekend Taian days in 2026 and 11 in 2027. All-Taian counts are 61 and 60, so what falls is Taian on Saturday and Sunday. Check public holidays with Japanese Public Holidays, and other lucky-day labels with the Lucky Days calendar. The arithmetic stays in the browser.

Every weekend Taian day, 2025–2027

2026 (11 Saturdays, 10 Sundays)

Saturdays: 24 Jan, 21 Feb, 28 Mar, 25 Apr, 30 May, 27 Jun, 25 Jul, 29 Aug, 26 Sep, 31 Oct, 28 Nov (no Saturday Taian in December).

Sundays: 22 Mar, 19 Apr, 24 May, 21 Jun, 19 Jul, 23 Aug, 20 Sep, 25 Oct, 22 Nov, 27 Dec (no Sunday Taian in January or February).

2025 (9 Saturdays, 11 Sundays)

Saturdays: 11 Jan, 8 Feb, 15 Mar, 12 Apr, 17 May, 14 Jun, 12 Jul, 20 Sep, 20 Dec (no Saturday Taian in August, October or November).

Sundays: 5 Jan, 2 Feb, 9 Mar, 6 Apr, 11 May, 8 Jun, 6 Jul, 17 Aug, 14 Sep, 19 Oct, 16 Nov.

2027 (7 Saturdays, 4 Sundays)

Saturdays: 2 Jan, 6 Feb, 5 Jun, 4 Sep, 2 Oct, 30 Oct, 4 Dec.

Sundays: 31 Jan, 7 Mar, 4 Apr, 28 Nov.

Why 2027 is about half: the lunar month reset

Rokuyo advances one step per lunar day, then the counter resets at a month change. Saturday 6 February 2027 is lunar 12/30, remainder 0, Taian. The next day, Sunday 7 February, is lunar 1/1, remainder (1+1) mod 6 = 2, Sensho. A plain +1 would have been Shakko; the month rollover jumps instead. That Sunday is not Taian.

Saturdays from March through May then mix Butsumetsu, Sensho, Tomobiki, Senbu and Shakko, because lunar month resets interrupt the cycle. They do not simply run Sensho → Tomobiki → Senbu → Butsumetsu. The next Saturday Taian is 5 June, lunar 5/1. In 2026, Saturday Taian instead repeats about every four to five weeks from 24 January through 28 November (11 times). December 2026 Saturdays fall in late lunar month 10 and in month 11, with remainders 1, 3, 4 and 5 (Shakko, Tomobiki, Senbu, Butsumetsu)—no Saturday Taian. Sunday 27 December is Taian.

FAQ

Is 2027's drop in weekend Taian days because there are fewer Taian days overall?
No. Taian days themselves are 61 in 2026 and 60 in 2027. What falls is Taian on Saturday and Sunday, because lunar month resets shift the six-day cycle against the week.
Why is there no Saturday Taian in December 2026?
December 2026 Saturdays fall in late lunar month 10 and in month 11, with remainders 1, 3, 4 and 5 (Shakko, Tomobiki, Senbu, Butsumetsu). The first Saturday, 5 December, is lunar 10/27. Sunday 27 December is Taian.
Is Taian scientifically lucky?
No. Rokuyo is calendar folklore with no scientific basis. It is only a custom for picking dates. The counts here run in the browser; nothing is sent to a server.

Counts and dates use the same rule as the Rokuyō calendar (Taian = remainder 0 of lunar month + day), enumerating every day in 2025–2027. Input never leaves the browser (2026-09-14).