Buddhists commemorate the day Sakyamuni attained enlightenment.
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culture
腊八节 (Làbā Jié, 8th day of the 12th lunar month) is celebrated as 释迦牟尼成道日 (the Buddha's enlightenment day). The customary 腊八粥 (eight-treasure rice porridge) traces back to a temple offering on this date.
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Religious vocabulary — primarily Buddhist, occasionally Daoist (where 成道 can mean 'achieving the Dao' or transcending). In secular speech, 'achieving enlightenment' figuratively is more often 顿悟 (dùnwù 'sudden realization').