Skip to content
Tong Shu Calendar Reference

Auspicious Business Opening Dates for August 2027開業 · August 2027

By Master Sean Chan · Updated

This month carries Li Qiu (立秋) — start of the BaZi autumn on August 8 (Singapore time): the BaZi calendar's sectional boundary for the month. Autumn proper begins with this term; Wood-day rankings tend to weaken from this point.Below is the universal Chinese metaphysics ranking of every day in August 2027 for opening a business (開市), derived from the classical Tong Shu (通書). Opening is treated as a 'beginning' — the rules favour 開 (Opening) and 建 (Establishing) officers and Yellow Dao days carrying 天德 / 月德 protection.

Top-ranked dates this month

31
days in August
27
pass hard requirements
6
rank as 上吉
5
top picks below
DateDay PillarOfficer 建除 Mansion 宿Clash 沖Class
12027-08-28壬午開 Opening鬼子 (Rat)上吉
22027-08-14戊辰成 Completing牛戌 (Dog)上吉
32027-08-05己未建 Establishing軫丑 (Ox)上吉
42027-08-03丁巳開 Opening張亥 (Pig)上吉
52027-08-08壬戌滿 Filling氐辰 (Dragon)上吉

All days in August 2027

DateDay PillarOfficerMansion ClashNotable factorsClass
2027-08-01乙卯成柳酉 Rooster建除 成 · 黃道吉
2027-08-02丙辰收星戌 Dog—平
2027-08-03丁巳開張亥 Pig建除 開 · 宿 張 · 黃道上吉
2027-08-04戊午閉翼子 Rat建除 閉凶
2027-08-05己未建軫丑 Ox天德合 · 月德合 · 宿 軫上吉
2027-08-06庚申除角寅 Tiger黃道吉
2027-08-07辛酉除亢卯 Rabbit四絕 · 宿 亢大凶
2027-08-08壬戌滿氐辰 Dragon月德 · 建除 滿 · 宿 氐上吉
2027-08-09癸亥平房巳 Snake天德 · 建除 平吉
2027-08-10甲子定心午 Horse黃道吉
2027-08-11乙丑執尾未 GoatFailed requirement: not_year_break大凶
2027-08-12丙寅破箕申 MonkeyFailed requirement: not_month_break大凶
2027-08-13丁卯危斗酉 Rooster月德合 · 建除 危 · 宿 斗吉
2027-08-14戊辰成牛戌 Dog天德合 · 建除 成 · 黃道上吉
2027-08-15己巳收女亥 Pig黃道吉
2027-08-16庚午開虛子 Rat建除 開 · 宿 虛吉
2027-08-17辛未閉危丑 Ox建除 閉 · 宿 危 · 黃道凶
2027-08-18壬申建室寅 Tiger月德吉
2027-08-19癸酉除壁卯 Rabbit天德吉
2027-08-20甲戌滿奎辰 Dragon建除 滿 · 黃道吉
2027-08-21乙亥平婁巳 Snake建除 平平
2027-08-22丙子定胃午 Horse黃道吉
2027-08-23丁丑執昴未 GoatFailed requirement: not_year_break大凶
2027-08-24戊寅破畢申 MonkeyFailed requirement: not_month_break大凶
2027-08-25己卯危觜酉 Rooster建除 危平
2027-08-26庚辰成參戌 Dog建除 成 · 宿 參 · 黃道上吉
2027-08-27辛巳收井亥 Pig宿 井 · 黃道吉
2027-08-28壬午開鬼子 Rat月德 · 建除 開上吉
2027-08-29癸未閉柳丑 Ox天德 · 建除 閉 · 黃道平
2027-08-30甲申建星寅 Tiger—平
2027-08-31乙酉除張卯 Rabbit宿 張吉
Personalised next step

BaZi-Aligned Date Report — August 2027

USD 388

A personalised PDF that re-ranks every business opening-suitable day in August 2027 against your BaZi (and, for weddings/ROM, your partner’s BaZi). It surfaces:

Order the report →

See the full glossary of classical date-selection terms in the BaZi Glossary & Auxiliary Stars.

Further reading from the blog

Selected posts from Master Sean Chan's blog covering this topic and closely related ones in practice:

Frequently asked

Why isn’t my day on the list of top 5?

The top list is the universal ranking before any personal adjustment. Many couples find their best date isn’t in the top 5. Once you account for your day pillars, the right day often shifts. That’s exactly the gap the BaZi-Aligned Date Report fills.

What does 大凶 mean and can it ever be overridden?

大凶 means the day fails a hard classical requirement: 月破 (month break), 歲破 (year break), or 四離/四絕 (a quarter-day boundary). These cannot be overridden by personal alignment; they are excluded categorically. Choose another day.

Why don’t you show times here?

Hour selection is personal. The right hour depends on your day pillar and the chosen day’s element relationship to it. Publishing universal “auspicious hours” misleads readers into thinking a generic hour is safe; it isn’t. Hours are included in the personalised report.

Where do these scores come from?

The classical Tong Shu (通書) tradition: 建除十二神 (Twelve Officers), 二十八宿 (Twenty-Eight Mansions), 月德 / 天德 (monthly and yearly virtue stars), 黃黑道 (Yellow/Black Dao), and the Dong Gong (董公) per-purpose rules. We compute these directly from astronomical solar terms — no app shortcuts.

Should I open the business on the same day as my company registration?

If you can — yes. Aligning the opening with the legal incorporation compounds the day’s influence on both events. If they have to be different, prioritise the opening (the customer-facing first day) over the registration date.

Methodology

Day pillars derive from the standard 60 Jiazi anchor (sexagenary day cycle, anchored against the published Tong Shu). Year pillars switch on Li Chun (立春), the first solar term of the BaZi year, computed from the truncated VSOP87 series for solar longitude. Month pillars switch on each sectional solar term. The Twelve Officers are the day branch’s offset from the month branch; the Twenty-Eight Mansions cycle every 28 days against an authoritative anchor.

Per-purpose rules follow the Dong Gong (董公擇日) tradition with adjustments encoded in our open purpose_rules.yaml. Scores are additive over the day’s present 神煞, the officer/mansion preference, and the Yellow Dao bonus, then clamped to 0–100 and classified.