Xia Calendar

February 4 is the beginning of spring, when ecliptic longitude is at 315 degrees. However, if you look at a current readout of ecliptic longitude you realize that some dates on the calendar need updating for ecliptic precession.

Here are the Xia calendar dates in agreement with 2009 astronomy, based on calculations for 18:00 (6 pm). That is because Chinese astronomers typically made observations at sundown.

Ecliptic Longitude	Date	Designation
315	February 4	Beginning of spring
330	February 18	Rains
345	March 5	Awakening insects
360	March 20	The vernal equinox occurs 11:44 UTC
15	April 5	Clear brightness
45	May 5	Grain rice
60	May 21	Small harvest
75	June 5	Seed planting
90	June 21	The summer solstice occurs 0:45 UTC
105	July 7	Minor heat -- aphelion on July 6, 02:00 UTC
120	July 23	Major heat
135	August 7	Beginning of autumn (Chinese seasons)
150	August 23	Limit of heat
165	Sept 7	White dew
180	Sept 23	Central division of autum (Chinese seasons) -- autumnal equinox occurs at 21:18 UTC on Sept 22
195	Oct 8	Cold dew
210	Oct 23	Descent of frost
225	Nov 7	Start of winter (Chinese seasons)
240	Nov 22	Minor snow
255	Dec 7	Major snow
270	Dec 22	Winter extreme (Chinese seasons)-- solstice occurs 17:47 UTC on Dec 21
285	Jan 5	Minor cold -- perhelion15:00 UTC on Jan 4
300	Jan 20	Major cold

Jieqi

The jieqi should also follow the astronomical year, as they are the "solar nodes." Here is a list of the jieqi according to 2009 astronomical calculations for 18:00 (6 pm).

Ecliptic Longitude	Chinese Month	Calendar Date	Western Star Marker (Cardinal Direction)
330	1	Feb 18
360	2	March 20	Pisces
30	3	April 20
60	4	May 21
90	5	June 21	Taurus
120	6	July 23
150	7	August 23
180	8	Sept 23	Virgo
210	9	Oct 23
240	10	Nov 22
270	11	Dec 22	Sagittarius
300	12	Jan 20