How long was the writing time before and after "Red Cliff Fu"?

Fu before and after Chibi is a common calligraphy work, which mostly uses the regular script strokes of the French king Wang Xizhi, and belongs to another style of regular script in Wen Zhiming. More interestingly, the writing time difference between the first and second poems is 25 years. Qianchibi Fu was written at the age of 6 1, while Houchibi Fu was written at the age of 86. At that time, Wen Zhiming was quite dissatisfied with Qianchibi Fu. "submersible ... the pen is slow and weak, but now I know how to use it, but I'm not smart enough." It can be seen that his lifelong pursuit of art is unremitting. It is said that when he was 90 years old, he wrote an epitaph, and he "sat up and died" before he finished writing it.