get_van_han
Calculate transit stars and active houses for a target Lunar year, month, or day to assess luck and predictions in Vietnamese Tử Vi horoscope.
Instructions
Calculate transit stars (sao lưu) and active houses (Đại Hạn, Tiểu Hạn, Nguyệt Hạn, Nhật Hạn) for the target Lunar period.
Purpose and Comparison
Use this tool to perform transit/vận hạn luck analysis (inspecting star shifts, Đại Hạn, Tiểu Hạn, monthly Nguyệt Hạn transits, and daily Nhật Hạn) for a specific target Lunar year, month, and optionally day.
Contrast with
generate_horoscope: Useget_van_hanspecifically for inspecting luck/predictions during a specific target timeframe. Usegenerate_horoscopeto get the static, base birth chart.
Side Effects, Auth, and Rate Limits
Side Effects: None. This is a read-only calculation and does not write to the database or render filesystem files.
Auth/Rate Limits: Runs entirely locally. No authentication or external rate limits apply.
Prerequisites & Calendar Conversions
CRITICAL: The parameters
current_year,current_month, and (if provided)current_dayrepresent the Lunar year, Lunar month, and Lunar day. If the user asks to inspect a specific Solar period (e.g., 'October 2026' or 'May 15th, 2026'), you MUST first use theconvert_calendartool to find the corresponding Lunar month/year/day before calling this tool.
Parameter Guidelines & Interactions
name: Name of the person.day: Day of birth (1-31).month: Month of birth (1-12).year: Year of birth.hour_val: Hour of birth (e.g., "14:30", "Ngọ"). Local civil time at the birthplace.gender_val: Gender ("Nam" or "Nữ").is_solar: True if birth date is Solar (Dương lịch), False if Lunar (Âm lịch).current_year: Target Lunar year to inspect (defaults to current system year, e.g., 2026).current_month: Target Lunar month to inspect (1-12, default 1).current_day: Target Lunar day to inspect (1-30, optional). When provided, also returnsnhat_han— the daily transit house derived from Nguyệt Hạn.timezone: Numeric UTC offset (default 7). Accepts integer (e.g.8) orh:30string (e.g."8:30"). Seegenerate_horoscope.timezonefor full spec.
Output Schema and Error Conditions
Returns: A dictionary containing:
person_details: Summary of demographic details (name, lunar birth date, etc.).target_period: Containscurrent_year,current_year_can_chi,current_month_lunar, andcurrent_agerepresenting the target period parameters.transit_stars: List of transit stars (e.g. Lưu Thái Tuế, Lưu Lộc Tồn) and their current coordinates/cung indexes.dai_han: Details of the active 10-year major cycle house.tieu_han: Details of the active 1-year minor cycle house.nguyet_han: Details of the active monthly cycle house.nhat_han: (only ifcurrent_dayis provided) Details of the active daily house, derived from Nguyệt Hạn.
Errors: Returns an error dictionary
{"error": "error_message"}if birth details are invalid, calculation fails, ortimezoneis malformed.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| day | No | ||
| name | No | Khách | |
| year | No | ||
| month | No | ||
| hour_val | No | 12:00 | |
| is_solar | No | ||
| timezone | No | ||
| gender_val | No | Nam | |
| current_day | No | ||
| current_year | No | ||
| current_month | No |