This small python programme is to accurately calculate the times (to millisecond) of 24 solar terms using JPL HORIZONS. 本python程式利用噴射推進實驗室的HORIZONS网上天文数据精确计算24节气时间（精确到毫秒）。
Install Python 3 (and its pip) and download the whole repository to your computer.
Install required python packages using the following command
python3 -m venv env
source env/bin/activate
pip install -r requirements.txt
HORIZONS has introduced rate limits to their service. To avoid going over the limits, default maximum thread number has been set to 2. If you still encounter timeout error, please wait a moment before performing new calculations.
In order for you local translations to work, you will need to compile the po file of your language into its binary mo file. Here is the example of how to do that for ja on linux.
$ cd locale/ja/LC_MESSAGES
$ msgfmt -o solarterms.mo solarterms
To compile po files on Windows, you can use poedit.
For usage, please see test.py. An example of running the test.py is listed below, where solar terms are different from those in the Northern Hemisphere.
$ source env/bin/activate
$ python test.py 2024 'Australia/Sydney'
Calculating solar terms from JPL HORIZONS data. Please wait...
WARNING: AstropyDeprecationWarning: ``id_type``s 'majorbody' and 'id' are deprecated and replaced with ``None``, which has the same functionality. [astroquery.jplhorizons.core]
WARNING: AstropyDeprecationWarning: ``id_type``s 'majorbody' and 'id' are deprecated and replaced with ``None``, which has the same functionality. [astroquery.jplhorizons.core]
Solar terms for 2024 will be (in the timezone of Australia/Sydney):
datetime ObsEclLon term
----------------------------- --------- --------------------
2024-Jan-06 07:49:23.550 AEDT 285.0 Minor Heat
2024-Jan-21 01:07:21.724 AEDT 300.0 Major Heat
2024-Feb-04 19:27:08.603 AEDT 315.0 Start of Autumn
2024-Feb-19 15:13:11.338 AEDT 330.0 End of Heat
2024-Mar-05 13:22:47.198 AEDT 345.0 White Dew
2024-Mar-20 14:06:25.232 AEDT 0.0 Autumn Equinox
2024-Apr-04 18:02:18.815 AEDT 15.0 Cold Dew
2024-Apr-19 23:59:46.598 AEST 30.0 Frost
2024-May-05 10:10:06.214 AEST 45.0 Start of Winter
2024-May-20 22:59:31.491 AEST 60.0 Minor Snow
2024-Jun-05 14:09:54.758 AEST 75.0 Major Snow
2024-Jun-21 06:51:00.836 AEST 90.0 Winter Solstice
2024-Jul-07 00:20:04.400 AEST 105.0 Minor Cold
2024-Jul-22 17:44:26.672 AEST 120.0 Major Cold
2024-Aug-07 10:09:17.336 AEST 135.0 Start of Spring
2024-Aug-23 00:55:03.794 AEST 150.0 Spring Showers
2024-Sep-07 13:11:21.660 AEST 165.0 Awakening of Insects
2024-Sep-22 22:43:40.375 AEST 180.0 Spring Equinox
2024-Oct-08 05:59:58.184 AEDT 195.0 Pure Brightness
2024-Oct-23 09:14:45.284 AEDT 210.0 Grain Rain
2024-Nov-07 09:20:05.465 AEDT 225.0 Start of Summer
2024-Nov-22 06:56:30.694 AEDT 240.0 Grain Buds
2024-Dec-07 02:17:03.601 AEDT 255.0 Grain in Ear
2024-Dec-21 20:20:35.169 AEDT 270.0 Summer Solstice
A second example is in Tokyo time and Japanese term names:
$ LANGUAGE=ja python test.py 2026 'Asia/Tokyo'
Calculating solar terms from JPL HORIZONS data. Please wait...
Solar terms for 2026 will be (in the timezone of Asia/Tokyo):
datetime ObsEclLon term
--------------------------- --------- ----
2026- 1-05 17:23:10.398 JST 285.0 小寒
2026- 1-20 10:44:57.008 JST 300.0 大寒
2026- 2-04 05:02:08.913 JST 315.0 立春
2026- 2-19 00:51:56.449 JST 330.0 雨水
2026- 3-05 22:59:00.103 JST 345.0 啓蟄
2026- 3-20 23:45:58.439 JST 0.0 春分
2026- 4-05 03:40:00.201 JST 15.0 清明
2026- 4-20 10:39:07.517 JST 30.0 穀雨
2026- 5-05 20:48:44.714 JST 45.0 立夏
2026- 5-21 09:36:45.366 JST 60.0 小満
2026- 6-06 00:48:22.909 JST 75.0 芒種
2026- 6-21 17:24:31.300 JST 90.0 夏至
2026- 7-07 10:56:58.281 JST 105.0 小暑
2026- 7-23 04:13:06.044 JST 120.0 大暑
2026- 8-07 20:42:45.300 JST 135.0 立秋
2026- 8-23 11:18:49.181 JST 150.0 処暑
2026- 9-07 23:41:17.964 JST 165.0 白露
2026- 9-23 09:05:13.910 JST 180.0 秋分
2026-10-08 15:29:18.271 JST 195.0 寒露
2026-10-23 18:37:57.077 JST 210.0 霜降
2026-11-07 18:52:05.163 JST 225.0 立冬
2026-11-22 16:23:21.405 JST 240.0 小雪
2026-12-07 11:52:32.330 JST 255.0 大雪
2026-12-22 05:50:15.050 JST 270.0 冬至