Calendar Casting: Plum Blossom's Most Used Hexagram Method — Year-Month-Day-Hour in Four Steps • TIMEACTOR

Why Shao Yong Chose the Lunar Calendar — The Logic Behind Calendar Casting

Glance at a Calendar and Cast a Hexagram

Calendar casting is the most frequently used plum blossom method. Shao Yong designed it on one simple idea: the rhythm of heaven and earth is hidden in time. Year, month, day, and hour are not random numbers. The year carries an Earthly Branch. The month carries a solar term. The day carries yin-yang balance. The hour carries flourishing and declining energy. Convert these four numbers into trigram numbers, and the hexagram emerges. No tools. No ritual. Just a glance at the lunar calendar.

Year = Earthly Branch number. Month = lunar month number. Day = lunar day number. Hour = Earthly Branch number. Upper trigram: sum of year+month+day ÷ 8, take remainder. Lower trigram: same sum. Moving line: sum of year+month+day+hour ÷ 6, take remainder. Four steps. Three seconds. One hexagram.

Worked Example: June 8, 2024 (Lunar), Wu Hour

Walk through a real date. 2024 = Jia Chen year. Chen is the 5th Earthly Branch → year=5. Sixth lunar month → month=6. Eighth lunar day → day=8. Wu hour is the 7th Earthly Branch → hour=7. Upper trigram: (5+6+8)=19, 19÷8=2 remainder 3 → Li trigram ☲. Lower trigram: same 19÷8=2 remainder 3 → Li trigram ☲. Both trigrams are Li. Original hexagram: Li Wei Huo ䷝. Moving line: (5+6+8+7)=26, 26÷6=4 remainder 2 → line 2 moves. Li hexagram line 2 moves, yin changes to yang, becoming Huo Tian Da You ䷍. The whole process: four numbers in, no tools needed.

Why Plum Blossom Uses the Lunar Calendar, Not the Gregorian

The Gregorian calendar is a solar calendar. It tracks the sun, not the moon. The lunar calendar is a lunisolar calendar — it follows both the sun (24 solar terms) and the moon (synodic months). The eight trigram system rests on yin-yang waxing and waning. Winter solstice births yang. Summer solstice births yin. All of these nodes live inside the lunar calendar's solar term system. Cast with a Gregorian date like March 15, and that same day could be the first lunar month or the second — completely different solar term positions. Lunar dates map naturally onto current yin-yang states. The first day of the month is the new moon — yin at its peak. The fifteenth is the full moon — yang at its peak. Gregorian dates carry none of this meaning. Earthly Branch numbers are themselves part of the lunar calendar system. All four numbers — year, month, day, hour — use branch numbers or lunar digits. The whole conversion stays inside one closed system. No external numerical noise.

Three Variations of Calendar Casting

Variation 1 — Standard: year+month+day gives trigrams, year+month+day+hour gives moving line. This is the most common. Variation 2 — Added quarter-hour: some practitioners subdivide the double-hour into quarters (8 per period) and add the quarter number to the moving line calculation. Higher precision, but not required. Variation 3 — Three-number version: if you don't know the hour, use only year, month, and day. Sum ÷8 for upper trigram, same sum ÷8 for lower trigram, same sum ÷6 for moving line. Missing the hour dimension costs some information, but it works in a pinch. When to use which? Have the time → four numbers. Don't have it → three numbers. Don't overthink it.

How to Interpret a Calendar-Cast Hexagram

Casting is step one. After you have the original hexagram and changed hexagram, examine ti-yong first. Which trigram is ti and which is yong? Plum blossom has no hard rule — generally, the trigram with the moving line is yong. The trigram without it is ti. If neither line moves? Schools differ. Shao Yong's original intent: 'what moves is yong, what stays still is ti.' Ti represents you, the querent. Yong represents the matter you asked about. Ti generates yong → you're consuming energy, investing heavily. Yong generates ti → the matter benefits you. Ti and yong in harmony → you and the matter are in sync, the ideal state. Yong overcomes ti → the matter is pressing on you. Be careful. Ti overcomes yong → you control the situation. Read the original hexagram's ti-yong together with the changed hexagram's ti-yong: the original is now, the changed is the direction. Example: original shows ti generating yong (you're investing), changed shows ti and yong in harmony (things smooth out after investing). That shift is a good signal.

Complete Calculation Rules for Calendar Casting

Year uses Earthly Branch order: Zi=1, Chou=2, Yin=3, Mao=4, Chen=5, Si=6, Wu=7, Wei=8, Shen=9, You=10, Xu=11, Hai=12. Do not use the Gregorian year. Do not confuse it with zodiac order.
Month uses the lunar month: first month=1, second=2, third=3…twelfth=12. Use the lunar month, not the Gregorian month. Leap months count as their base month — no extra number.
Day uses the lunar day: first day=1, second=2…thirtieth=30. Again, use the lunar day, not the Gregorian date.
Hour uses Earthly Branch order: Zi hour (23:00-01:00)=1, Chou (01:00-03:00)=2…Hai (21:00-23:00)=12. Match the double-hour period to its branch.
Upper trigram: (year + month + day) ÷ 8, take the remainder. 1=Qian, 2=Dui, 3=Li, 4=Zhen, 5=Xun, 6=Kan, 7=Gen, 0=Kun.
Lower trigram: (year + month + day) ÷ 8, same sum. Upper and lower trigrams can be identical — that gives you an eight-pure hexagram.
Moving line: (year + month + day + hour) ÷ 6, take the remainder. 1=line 1 moves, 2=line 2 moves…5=line 5 moves, 0=line 6 (top line) moves.

Common Breakers

Using Gregorian year, month, and day to cast. Plum blossom's time system rests on the lunar calendar and Earthly Branches. Gregorian numbers carry no trigram meaning. A remainder from 2024÷8 has nothing to do with the hexagram system.
Mixing up the month's Earthly Branch number with the year's. Yin month=3, but that doesn't mean Yin year=3. Years must first convert to Earthly Branches, then take the order number. 2024 is a Jia Chen year — Chen=5.
Using different sums for upper and lower trigrams. Both trigrams use the same year+month+day sum divided by 8. Many people add the hour to the upper trigram and add it again to the lower. Wrong. The hour only enters the moving line calculation.
Subtracting before dividing when taking remainders. Example: year+month+day=38. Some people reduce 38 to 32 (4×8) then take remainder 6. Just do 38÷8=4 remainder 6. Same math, fewer steps to mess up.
Treating remainder 0 as 'line 0.' The trigram system has no line 0. When dividing by 6 gives remainder 0, that's line 6 (top line) moving.

Calendar Casting in Four Dimensions: Career, Love, Personality, Health

Career & Wealth

Career and wealth questions suit calendar casting naturally. You're wondering whether to switch jobs. Today is the third lunar month, fifth day, Chen hour. The original hexagram shows ti generating yong — your current job is draining you. The changed hexagram shows yong generating ti — things reverse after the move. This combination reads: 'tiring now, better after the change.' Note the month's influence. Spring (Yin, Mao, Chen months) — wood flourishes. If your ti trigram is Zhen or Xun, the seasonal energy boosts your opportunities. Autumn (Shen, You, Xu months) — metal flourishes. Ti trigram as Dui or Qian benefits negotiation and contract signing.

Love & Relationship

For relationships, the birth year's Earthly Branch matters. You're a Zi-year person. They're a Wu-year person. Zi and Wu clash. If Zi numbers (1) or Wu numbers (7) keep appearing in the casting date, the clash is amplified. Plum blossom has a special angle on relationships: the year number represents your foundation. The hour number represents their foundation. Year÷8 remainder versus hour÷8 remainder — if they form a generating cycle (e.g., you Qian, them Kun → metal generates earth), the relationship base is solid. If they clash (e.g., you Zhen, them Qian → metal overcomes wood), one party gets suppressed.

Personality

People who gravitate toward calendar casting share some traits. They know the lunar calendar well. A natural yin-yang waxing-waning calendar runs in their head. They move with rhythm — they feel what to do and when. They dislike complex tools. If something works with what's already in front of them, they won't add steps. Calendar casting suits them as an entry point to plum blossom. Watch for one tendency: relying purely on time-based casting can produce similar hexagram types over and over. Similar time windows produce similar number combinations. Occasionally switch to number casting or object casting to break the pattern.

Health

Health questions with calendar casting reveal your current physical state. The lunar month is especially telling. First month (Yin month) governs the liver. If your ti trigram is Zhen or Xun and yong overcomes it, liver qi may be off. Fifth month (Wu month) governs the heart. Ti trigram Li overcome by Kan — watch the cardiovascular system. On ti-yong relations: ti generating yong means your body is 'supplying energy' to the outside world — likely from overwork, sleep debt, or mental drain. Yong overcoming ti means external factors are hurting you — pollution, poor diet, seasonal illness. A changed hexagram with ti-yong harmony or shifting from ti-generates-yong to yong-generates-ti signals your body is heading in a better direction.

Core Verses of Calendar Casting

Practical Tips for Calendar Casting

Cast a Hexagram Every Morning to Build Muscle Memory: Don't think of a question. Just take today's year, month, day, and hour, cast the hexagram, and look at the ti-yong relationship between original and changed hexagrams. Do it for a month. Ti-yong generating and overcoming becomes muscle memory. When a real question comes, you'll cast three times faster than most people. The biggest barrier for beginners isn't getting the math wrong — it's being slow. Being slow breeds self-doubt. Doubt makes you slower. Train casting until it's as natural as breathing.
Put the Earthly Branch Order on Your Phone Wallpaper: Zi=1, Chou=2, Yin=3, Mao=4, Chen=5, Si=6, Wu=7, Wei=8, Shen=9, You=10, Xu=11, Hai=12. It's normal not to memorize it. Don't force it. Screenshot it, set it as your wallpaper. By day six, you'll know it without looking. Same for the lunar date — your phone calendar shows it with one tap. Don't use your brain to store what your phone can show you.
Review Historical Casts Before Big Decisions: What hexagram came up on this date last year? The year before? If the same time window produces similar ti-yong patterns across consecutive years, there's a real rhythm in that window. Skilled plum blossom practitioners do this — they don't look at a single hexagram. They look at patterns across a time series.

Calendar Casting FAQ

Q:How do leap months work? For example, a leap sixth lunar month — is the month number 6 or 7?

Use 6. Leap months don't change the month number. A leap sixth month is still the sixth month — it just has an extra month in solar term positioning. From a casting perspective, the solar term energy hasn't shifted. The yin-yang position hasn't changed. So the month number stays the same.

Q:What if I don't know the exact double-hour? Say I only know it's 'morning' but not the specific time.

Several ways to handle this. The honest way: use only year+month+day with three numbers. You lose a dimension of information, but you don't guess. If you must add a time, morning is likely between Chen hour (7-9, number 5) and Wu hour (11-13, number 7). Take the midpoint, Si hour (9-11, number 6), as an approximation. It's a compromise. Accuracy takes a hit, but it's better than no time at all.

Q:Does calendar casting need to account for solar terms? Before Li Chun (Start of Spring), is it still the previous year?

Strictly speaking, the year boundary is Li Chun. A baby born before Li Chun still carries the previous year's zodiac sign. But plum blossom's calendar casting can relax this slightly — daily casting cares about the current yin-yang state, not the precise astronomical boundary. Around Li Chun, yin and yang are already in transition. A difference of 1 in the year number usually doesn't change the final hexagram much. Unless your matter demands extreme precision, don't agonize over it.

Q:How many times can I cast with calendar casting in one day? Won't the same double-hour always give the same hexagram?

Within the same double-hour, the base numbers are identical, so the hexagram is identical. This means with calendar casting, you can only effectively cast once per double-hour. If you have three questions in the same two-hour window, use number casting or object casting for the other two. This isn't a bug — it's plum blossom's flexibility at work. The same question has multiple casting methods available.