(2) Divide by 4, discarding any fraction.
除4取商,小数不要。
(3) Add the day of the month.
加上日期数。
(4) Add the month's key value: JFM AMJ JAS OND: 033
614 625 035
加上月值(1月~12月):033 614 625 035
(5) Subtract 1 for January or February of a leap
year.
闰年1月和2月要减1。
(6) For a Gregorian date, add 0 for 1900's, 6 for
2000's, 4 for 1700's, 2 for 1800's; for other
years, add or subtract multiples of 400.
...21世纪(2000's)加6...
(7) Add the last two digits of the year.
再加上年的后2位数。