Module calendrical_calculations::chinese_based

Chinese-like lunar calendars (Chinese, Dangi)

Structs

• Chinese
  A type implementing ChineseBased for the Chinese calendar
• ChineseFromFixedResult
  chinese_based_date_from_fixed returns extra things for use in caching
• Dangi
  A type implementing ChineseBased for the Dangi (Korean) calendar
• YearBounds
  Marks the bounds of a lunar year

Constants

• CHINESE_EPOCH 🔒
• CHINESE_EPOCH_ISO 🔒
• CHINESE_LOCATION_POST_1929 🔒
• CHINESE_LOCATION_PRE_1929 🔒
• FIXED_1908 🔒
• FIXED_1912 🔒
• FIXED_1954 🔒
• FIXED_1961 🔒
• KOREAN_ELEVATION 🔒
• KOREAN_EPOCH 🔒
• KOREAN_EPOCH_ISO 🔒
• KOREAN_LATITUDE 🔒
• KOREAN_LOCATION_1908 🔒
• KOREAN_LOCATION_1912 🔒
• KOREAN_LOCATION_1954 🔒
• KOREAN_LOCATION_1961 🔒
• KOREAN_LOCATION_ORIGINAL 🔒
• KOREAN_LONGITUDE 🔒
• MAX_ITERS_FOR_MONTHS_OF_YEAR 🔒
• UTC_OFFSET_1908 🔒
• UTC_OFFSET_1912 🔒
• UTC_OFFSET_1954 🔒
• UTC_OFFSET_1961 🔒
• UTC_OFFSET_ORIGINAL 🔒
  The Korean Dangi calendar relies on knowing the current day at the moment of a new moon; however, this can vary depending on location. As such, new moon calculations are based on the time in Seoul. Before 1908, local time was used, represented as UTC+(3809/450 h). This changed multiple times as different standard timezones were adopted in Korea. Currently, UTC+9h is used.
• UTC_OFFSET_POST_1929 🔒
• UTC_OFFSET_PRE_1929 🔒
  The Chinese calendar relies on knowing the current day at the moment of a new moon; however, this can vary depending on location. As such, new moon calculations are based on the time in Beijing. Before 1929, local time was used, represented as UTC+(1397/180 h). In 1929, China adopted a standard time zone based on 120 degrees of longitude, meaning from 1929 onward, all new moon calculations are based on UTC+8h.

Traits

• ChineseBased
  The trait ChineseBased is used by Chinese-based calendars to perform computations shared by such calendar. To do so, calendars should:

Functions

• bind_winter_solstice 🔒
  This function forces the RataDie to be on December 20, 21, 22, or 23. It was created for practical considerations and is not in the text.
• chinese_based_date_from_fixed
  Get a chinese based date from a fixed date, with the related ISO year
• days_in_month
  Returns the number of days in the given month after the given new_year. Also returns the RataDie of the new moon beginning the next month.
• days_in_prev_year
  Given a new year, calculate the number of days in the previous year
• days_in_provided_year
  Calculated the numbers of days in the given year
• days_until_month
  Given the new year and a month/day pair, calculate the number of days until the first day of the given month
• fixed_mid_year_from_year
  Get a RataDie in the middle of a year; this is not necessarily meant for direct use in calculations; rather, it is useful for getting a RataDie guaranteed to be in a given year as input for other calculations like calculating the leap month in a year.
• get_leap_month_from_new_year
  Given that new_year is the first day of a leap year, find which month in the year is a leap month. Since the first month in which there are no major solar terms is a leap month, this function cycles through months until it finds the leap month, then returns the number of that month. This function assumes the date passed in is in a leap year and tests to ensure this is the case in debug mode by asserting that no more than thirteen months are analyzed.
• is_leap_year
  Whether this year is a leap year
• last_month_day_in_year
  The last month and day in this year
• major_solar_term_from_fixed 🔒
  Get the current major solar term of a fixed date, output as an integer from 1..=12.
• midnight 🔒
  Universal time of midnight at start of a Moment’s day at the observation location
• month_days
  Returns the number of days in the given (year, month). In the Chinese calendar, months start at each new moon, so this function finds the number of days between the new moon at the beginning of the given month and the new moon at the beginning of the next month.
• month_structure_for_year
  Returns the length of each month in the year, as well as a leap month index (1-indexed) if any. Month lengths are stored as true for 30-day, false for 29-day. In the case of no leap months, month 13 will have value false.
• new_moon_before 🔒
  The fixed date in standard time at the observation location of the previous new moon before a given Moment.
• new_moon_on_or_after 🔒
  The fixed date in standard time at the observation location of the next new moon on or after a given Moment.
• new_year_in_sui 🔒
  Determines the fixed date of the lunar new year given the start of its corresponding solar year (歲), which is also the winter solstice
• new_year_on_or_before_fixed_date 🔒
  Get the fixed date of the nearest Lunar New Year on or before a given fixed date. This function also returns the solstice following a given date for optimization (see #3743).
• winter_solstice_on_or_before 🔒
  Get the fixed date of the nearest winter solstice, in the Chinese time zone, on or before a given fixed date.