Skip to content
Tong Shu Calendar Reference

Auspicious Renovation Start Dates for September 2026裝修 · September 2026

By Master Sean Chan · Updated

This month carries Bai Lu (白露) — month flips to 酉 on September 7 (Singapore time): the BaZi calendar's sectional boundary for the month. Below is the universal Chinese metaphysics ranking of every day in September 2026 for breaking ground on renovation (動土 / 修造), derived from the classical Tong Shu (通書). Renovation is an Earth-disturbing act and is more sensitive to Earth-related taboos than weddings or business openings.

Top-ranked dates this month

30
days in September
26
pass hard requirements
3
rank as 上吉
5
top picks below
DateDay PillarOfficer 建除 Mansion 宿Clash 沖Class
12026-09-02壬午開 Opening翼子 (Rat)上吉
22026-09-25乙巳成 Completing井亥 (Pig)上吉
32026-09-10庚寅執 Holding箕申 (Monkey)上吉
42026-09-30庚戌除 Removing翼辰 (Dragon)吉
52026-09-13癸巳成 Completing女亥 (Pig)吉

All days in September 2026

DateDay PillarOfficerMansion ClashNotable factorsClass
2026-09-01辛巳收張亥 Pig宿 張 · 黃道吉
2026-09-02壬午開翼子 Rat月德 · 建除 開上吉
2026-09-03癸未閉軫丑 Ox天德 · 建除 閉 · 黃道平
2026-09-04甲申建角寅 Tiger建除 建平
2026-09-05乙酉除亢卯 Rabbit宿 亢平
2026-09-06丙戌滿氐辰 Dragon宿 氐 · 黃道平
2026-09-07丁亥滿房巳 Snake—平
2026-09-08戊子平心午 HorseFailed requirement: not_year_break大凶
2026-09-09己丑定尾未 Goat建除 定吉
2026-09-10庚寅執箕申 Monkey月德 · 建除 執 · 宿 箕上吉
2026-09-11辛卯破斗酉 RoosterFailed requirement: not_month_break大凶
2026-09-12壬辰危牛戌 Dog建除 危凶
2026-09-13癸巳成女亥 Pig建除 成吉
2026-09-14甲午收虛子 Rat宿 虛 · 黃道吉
2026-09-15乙未開危丑 Ox月德合 · 建除 開 · 宿 危吉
2026-09-16丙申閉室寅 Tiger建除 閉凶
2026-09-17丁酉建壁卯 Rabbit建除 建 · 宿 壁 · 黃道平
2026-09-18戊戌除奎辰 Dragon宿 奎吉
2026-09-19己亥滿婁巳 Snake—平
2026-09-20庚子平胃午 HorseFailed requirement: not_year_break大凶
2026-09-21辛丑定昴未 Goat建除 定吉
2026-09-22壬寅執畢申 Monkey四離 · 建除 執 · 黃道凶
2026-09-23癸卯破觜酉 RoosterFailed requirement: not_month_break大凶
2026-09-24甲辰危參戌 Dog建除 危凶
2026-09-25乙巳成井亥 Pig月德合 · 建除 成上吉
2026-09-26丙午收鬼子 Rat黃道吉
2026-09-27丁未開柳丑 Ox建除 開 · 黃道吉
2026-09-28戊申閉星寅 Tiger建除 閉凶
2026-09-29己酉建張卯 Rabbit建除 建 · 宿 張 · 黃道平
2026-09-30庚戌除翼辰 Dragon月德吉
Personalised next step

BaZi-Aligned Date Report — September 2026

USD 388

A personalised PDF that re-ranks every renovation-suitable day in September 2026 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.

What is 土王用事 and why is groundbreaking restricted then?

土王用事 are the four 18-day windows around each seasonal transition when the Earth phase is dominant. Disturbing the ground during these windows is taboo for renovation, foundation work, and excavation. The page’s hard-requirement filter excludes these days; for a personal alignment we also check your Earth-element balance.

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.