How to Calculate Start of Winter?
According to ancient records, there are three signs to look for that the Start of Winter period has begun. The first sign is that water begins to freeze. The second sign is that the ground has also begun to freeze. The third sign is that animals such as pheasants can no longer be seen, while clams with similar colors to pheasants begin to appear on beach.
The understanding of Start of Winter can’t be limited to its literal meaning, which refers to the start of winter. “Li” in Chinese means “start,” and “Dong” means “end,” and crops harvested in autumn should be stored up. Start of winter doesn’t simply imply that winter is coming. It also implies that people should store things for the winter and keep the cold out.
Formula: [Y * D + C]-L
Note: Y refers to the last two digits of a year, such as 10 in 2010, 08 in 2008, D=0.2422, L=the number of leap years, 21st century C=7.438, 20th century C= 8.218.
Example: The date of Start of Winter in 2088= [88 × 0.2422 +7.438] - [88 / 4] = 28-22 = 6, so Start of Winter falls on Nov 6. Exceptions: For 2089, add one to the calculated result.