Accurately calculate traditional memorial dates including the First Seven, Third Seven, Fifth Seven, and Seventh Seven. Supports both Lunar and Gregorian calendar inputs to help families follow traditional mourning customs.
计算说明:根据传统习俗,去世当天算作第一天,头七即第七天(去世日期+6天)。百日为第100天(去世日期+99天)。周年祭通常为去世日期次年的同月同日。

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After the passing of a loved one, families often miss important memorial dates due to unfamiliarity with traditional customs. Based on the date of passing, this tool strictly follows the traditional "Zuo Qi" (Doing Seven) algorithm to automatically calculate the corresponding Gregorian dates for the First Seven (7th day), Third Seven (21st day), Fifth Seven (35th day), and Seventh Seven (49th day). The "First Seven" refers to the seventh day after the deceased's passing, traditionally believed to be the day the soul returns home to visit.
Counting from the day after passing, the 7th day is the First Seven (e.g., if the passing occurred on November 15, the First Seven is November 21).
The Lunar calendar involves complex rules like leap months. If entering a Lunar date before 1900 or a specific leap month, we recommend verifying it through a Gregorian reverse check. The tool's built-in Lunar conversion is based on standard algorithms, but minor discrepancies may occur for extreme historical dates.
Please ensure the entered date is completely accurate, as any error will skew all subsequent results. Regional customs may interpret the exact hours of "Zuo Qi" differently; this tool provides date references only. When handling sensitive personal information, we recommend using a private device.
In traditional mourning customs, the "Fifth Seven" (35th day) is believed to influence the deceased's reincarnation, so we highly recommend prioritizing the accuracy of this date. Typical input example: A Gregorian passing date of 2023-11-15 corresponds to a First Seven on 2023-11-21 and a Seventh Seven on 2024-01-02.