十二消息卦
十二卦對應十二個月：從冬至一陽來復，到立春三陽開泰，到立夏純陽至乾，到夏至一陰始姤，再到立冬純陰入坤，一年之中陰陽的消長，形成完整的循環。古代把這個循環稱為「卦氣」，是易經與天文曆法接軌的核心之一。
Twelve hexagrams map to the twelve months. One yang returns at the winter solstice (Fu), three yang open the spring at the start of the year (Tai), yang is complete at the start of summer (Qian); one yin appears at the summer solstice (Gou), and yin is complete at the start of winter (Kun). The old name for this scheme is guaqi, "hexagrams and seasonal qi," one of the main places where the Yijing meets the calendar.
第 20 卦 觀Hex 20 · 觀 · Guan · Contemplation
秋分，陰已過半。觀察、靜觀、收斂。
At the autumn equinox, yin has passed its midpoint. Observe, contemplate, gather inward.
怎麼讀這個輪盤
頂部十二點鐘方向是乾卦（四月，巳月，純陽巔峰）。從這裡順時針走，每過三十度 就進入下一個月。陽氣開始消退（姤、遯⋯），到六點鐘方向（十月，亥月）就是純陰的坤卦。 然後一陽來復，繼續順時針上升，回到頂部，完成一年。
朱紅色小點標記今日對應的卦。中央圓盤顯示目前作用中的卦（預設今日的卦，滑鼠移到哪一卦就切換過去），並附上該位置在循環中的說明。
應用方法：每個月進入新的節氣時，回到這個輪盤看當月的卦， 讀它的完整內容。一整年走下來，你自然就內化了十二卦，以及整個陰陽消息的循環。 這比一卦一卦死記強很多。
Top (12 o'clock) is Qian, yang at its peak (the fourth lunar month). Going clockwise, every 30° advances one month. Yang recedes through Gou, Dun and onward; at 6 o'clock (the tenth month) we reach pure-yin Kun. Then yang returns at Fu and the cycle climbs back to the top. The vermilion dot marks today's corresponding hexagram. The center disc shows the active hexagram (today's by default; hover any to switch), with a note on that position in the cycle. Operationally: each month as a new solar term begins, return to this wheel and read the current month's hexagram in depth. After a full year, you will have internalized all twelve and the whole cycle of yin and yang waxing and waning, far more effective than memorizing hexagrams individually.
十二消息卦的歷史地位
「消息」二字出自《彖傳》：「君子尚消息盈虛，天行也。」消是衰退，息是生長。十二消息卦 是漢代卦氣說的骨架，西漢孟喜、京房把它系統化，後世的占卜、風水、奇門、命理也常沿用這套時令框架。
用這個輪盤，是把手上的事放進消長裡看：它正在長，已到頂，還是開始退。 同一套消長可以放在一年裡看，也可以放在一件事的起落裡看，位置看清了，該進該守也就有了分寸。
The word xiaoxi comes from the Tuan Zhuan of Bo: "The gentleman honors the waning and waxing, the filling and emptying; this is the course of heaven." Xiao is decline, xi is growth. The twelve hexagrams are the frame of Han-dynasty guaqi theory, systematized by the Western Han scholars Meng Xi and Jing Fang, and later borrowed by divination, fengshui, qimen and natal astrology.
Using the wheel means placing the matter in hand inside this rise and fall: is it growing, at its height, or starting to recede? The same pattern can be read across a year or across the life of a single undertaking. Once the position is clear, you know better when to press on and when to hold.