曜日已是人们日常生活中一个重要的记日方法,用格列高利历(即现时的公历)与回历均可推算其岁首曜日。但前者因建历后又多次改历,因此没有一种简单的方法推算各年首曜日,现用格列高利历推算岁首曜日,除需有冗长的数表外,还需各年的推算参数①②。后者则不然,其建历后既未作过改历,所建立的推算回历岁首曜日的三种方法,不仅简便,且至今仍能沿用。 回历包括回回宫分历(属太阳历)及回回月分历(属太阴历)两种,前者以地球绕日左旋一周而分寒暑,白今年春分点至次年春分点历365日4时48分45秒,较之现测算的数字,年少一秒,积86400年而少一日;后者以月绕地球一周为27日7时43分11.5秒,而又为与太阳 Day of the sun is already an important method of mind-keeping in daily life. The Gregorian calendar (the present Gregorian calendar) and the Hui calendar can be used to calculate the date of their first Sunday. However, the former has repeatedly changed the calendar because of its construction. Therefore, there is no simple way to calculate the first Yao day of each year. The current Gregorian calendar is on the first day of the first year. In addition to the lengthy number list, Calculate the parameters ① ②. The latter is not the case. The three methods of calculating the first day of the first lunar month are not only simple but can still be used up to now. Back to the calendar, including the return to the palace calendar (solar calendar) and the return of the month calendar (lunar calendar) two, the former left to earth for one week around the Earth and the cold and heat, white and the vernal equinox to the following year ores calendar 365 日 4:48 45 Seconds, compared with the figures now measured, one second per year, accumulate 86400 years and less day; the latter to the moon around the earth for a week at 7:43 on the 27th 11.5 seconds, but with the sun