24节气是根据天地运行规律来确定四季循环的起点与终点并划分出二十四节气。将太阳周年运动轨迹划分为24等份，每一等份为一个“节气”，统称“二十四节气”。
二十四节气以地球围绕太阳公转的一个周期作为一个轮回，基本概括了一年中不同时节太阳在黄道上位置的不同、寒来暑往的准确时间、降雨降雪等自然现象发生的规律，以及记载了大自然中一些物候现象的时刻。
php获取二十四节气，php判断某一天是否是某个节气，代码如下：
/**
* @param int $time
* @return mixed|string
*/
function getJieQi($time = 0) {
date_default_timezone_set('Asia/Shanghai');
!$time && $time = time();
list($year, $month, $day) = explode('-', date('Y-m-d', $time));
$solar_term = [
0 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1901
1 => [621, 519, 621, 621, 622, 722, 824, 824, 824, 924, 823, 823], //1902
2 => [621, 520, 722, 621, 722, 722, 824, 924, 924, 924, 823, 823], //1903
3 => [721, 520, 621, 520, 621, 622, 723, 823, 823, 824, 823, 722], //1904
4 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1905
5 => [621, 519, 621, 621, 622, 622, 824, 824, 824, 924, 823, 823], //1906
6 => [621, 520, 722, 621, 722, 722, 824, 924, 924, 924, 823, 823], //1907
7 => [721, 520, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1908
8 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1909
9 => [621, 519, 621, 621, 622, 622, 824, 824, 824, 924, 823, 823], //1910
10 => [621, 520, 722, 621, 722, 722, 824, 924, 924, 924, 823, 823], //1911
11 => [721, 520, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1912
12 => [620, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1913
13 => [621, 419, 621, 521, 622, 622, 824, 824, 824, 924, 823, 823], //1914
14 => [621, 520, 622, 621, 622, 722, 824, 824, 924, 924, 823, 823], //1915
15 => [621, 520, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1916
16 => [620, 419, 621, 521, 621, 622, 823, 824, 823, 924, 823, 722], //1917
17 => [621, 419, 621, 521, 622, 622, 824, 824, 824, 924, 823, 822], //1918
18 => [621, 520, 622, 621, 622, 722, 824, 824, 924, 924, 823, 823], //1919
19 => [621, 520, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1920
20 => [620, 419, 621, 520, 621, 622, 823, 824, 823, 924, 823, 722], //1921
21 => [621, 419, 621, 521, 622, 622, 824, 824, 824, 924, 823, 822], //1922
22 => [621, 519, 621, 621, 622, 722, 824, 824, 924, 924, 823, 823], //1923
23 => [621, 520, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1924
24 => [620, 419, 621, 520, 621, 622, 823, 824, 823, 924, 823, 722], //1925
25 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1926
26 => [621, 519, 621, 621, 622, 722, 824, 824, 824, 924, 823, 823], //1927
27 => [621, 520, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1928
28 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1929
29 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1930
30 => [621, 519, 621, 621, 622, 722, 824, 824, 824, 924, 823, 823], //1931
31 => [621, 520, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1932
32 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1933
33 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1934
34 => [621, 519, 621, 621, 622, 622, 824, 824, 824, 924, 823, 823], //1935
35 => [621, 520, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1936
36 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1937
37 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1938
38 => [621, 519, 621, 621, 622, 622, 824, 824, 824, 924, 823, 823], //1939
39 => [621, 520, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1940
40 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1941
41 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1942
42 => [621, 519, 621, 621, 622, 622, 824, 824, 824, 924, 823, 823], //1943
43 => [621, 520, 621, 520, 521, 621, 723, 823, 823, 823, 722, 722], //1944
44 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1945
45 => [620, 419, 621, 521, 622, 622, 823, 824, 823, 924, 823, 822], //1946
46 => [621, 419, 621, 521, 622, 622, 824, 824, 824, 924, 823, 823], //1947
47 => [621, 520, 521, 520, 521, 621, 723, 723, 823, 823, 722, 722], //1948
48 => [520, 419, 621, 520, 621, 622, 723, 824, 823, 824, 822, 722], //1949
49 => [620, 419, 621, 520, 621, 622, 823, 824, 823, 924, 823, 822], //1950
50 => [621, 419, 621, 521, 622, 622, 824, 824, 824, 924, 823, 823], //1951
51 => [621, 520, 521, 520, 521, 621, 723, 723, 823, 823, 722, 722], //1952
52 => [520, 419, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1953
53 => [620, 419, 621, 520, 621, 622, 823, 824, 823, 923, 823, 722], //1954
54 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1955
55 => [621, 520, 520, 520, 521, 621, 723, 723, 823, 823, 722, 722], //1956
56 => [520, 419, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1957
57 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1958
58 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1958
59 => [621, 519, 520, 520, 521, 621, 723, 723, 723, 823, 722, 722], //1960
60 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1961
61 => [621, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1962
62 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1963
63 => [621, 519, 520, 520, 521, 621, 723, 723, 723, 823, 722, 722], //1964
64 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1965
65 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1966
66 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1967
67 => [621, 519, 520, 520, 521, 521, 723, 723, 723, 823, 722, 722], //1968
68 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1969
69 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1970
70 => [621, 419, 621, 521, 622, 622, 823, 824, 824, 924, 823, 822], //1971
71 => [621, 519, 520, 520, 521, 521, 723, 723, 723, 823, 722, 722], //1972
72 => [520, 420, 621, 520, 521, 621, 723, 823, 823, 823, 722, 722], //1973
73 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1974
74 => [621, 419, 621, 521, 622, 622, 823, 824, 823, 924, 823, 822], //1975
75 => [621, 519, 520, 420, 521, 521, 723, 724, 723, 823, 722, 722], //1976
76 => [520, 419, 621, 520, 621, 621, 723, 723, 823, 823, 722, 722], //1977
77 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 824, 823, 722], //1978
78 => [621, 419, 621, 521, 621, 622, 823, 824, 823, 924, 823, 822], //1979
79 => [621, 519, 520, 420, 521, 521, 723, 723, 723, 823, 722, 722], //1980
80 => [520, 419, 621, 520, 521, 621, 723, 723, 823, 823, 822, 722], //1981
81 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1982
82 => [620, 419, 621, 520, 621, 622, 823, 824, 823, 924, 823, 822], //1983
83 => [621, 419, 520, 420, 521, 521, 722, 723, 723, 823, 722, 722], //1984
84 => [520, 419, 521, 520, 521, 621, 723, 723, 823, 823, 722, 722], //1985
85 => [520, 419, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //1986
86 => [620, 419, 621, 520, 621, 622, 723, 824, 823, 924, 823, 722], //1987
87 => [621, 419, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //1988
88 => [520, 419, 520, 520, 521, 621, 723, 723, 723, 823, 722, 722], //1989
89 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 824, 822, 722], //1990
90 => [620, 419, 621, 520, 721, 622, 723, 823, 823, 924, 823, 722], //1991
91 => [621, 419, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //1992
92 => [520, 418, 520, 520, 521, 621, 723, 723, 723, 823, 722, 722], //1993
93 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1994
94 => [620, 419, 621, 520, 621, 622, 723, 821, 823, 924, 823, 722], //1995
95 => [621, 419, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //1996
96 => [520, 418, 520, 520, 521, 521, 723, 723, 723, 823, 722, 722], //1997
97 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //1998
98 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //1999
99 => [621, 419, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //2000
100 => [520, 418, 520, 520, 521, 521, 723, 723, 723, 823, 722, 722], //2001
101 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //2002
102 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //2003
103 => [621, 419, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //2004
104 => [520, 418, 520, 520, 521, 521, 723, 723, 723, 823, 722, 722], //2005
105 => [520, 419, 621, 520, 521, 621, 723, 723, 823, 823, 722, 722], //2006
106 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 924, 823, 722], //2007
107 => [621, 419, 520, 420, 521, 521, 722, 723, 722, 823, 722, 721], //2008
108 => [520, 418, 520, 420, 521, 521, 723, 723, 723, 823, 722, 722], //2009
109 => [520, 419, 621, 520, 521, 621, 723, 723, 823, 823, 722, 722], //2010
110 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 824, 823, 722], //2011
111 => [621, 419, 520, 420, 520, 521, 722, 723, 722, 823, 722, 721], //2012
112 => [520, 418, 520, 420, 521, 521, 722, 723, 723, 823, 722, 722], //2013
113 => [520, 419, 621, 520, 521, 621, 723, 723, 823, 823, 722, 722], //2014
114 => [620, 419, 621, 520, 621, 622, 723, 823, 823, 824, 822, 722], //2015
115 => [620, 419, 520, 419, 520, 521, 722, 723, 722, 823, 722, 721], //2016
116 => [520, 318, 520, 420, 521, 521, 722, 723, 723, 823, 722, 722], //2017
117 => [520, 419, 521, 520, 521, 621, 723, 723, 823, 823, 722, 722], //2018
118 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 824, 822, 722], //2019
119 => [620, 419, 520, 419, 520, 521, 622, 722, 722, 823, 722, 721], //2020
120 => [520, 318, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //2021
121 => [520, 419, 520, 520, 521, 621, 723, 723, 723, 823, 722, 722], //2022
122 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 824, 822, 722], //2023
123 => [620, 419, 520, 419, 520, 521, 622, 722, 722, 823, 722, 621], //2024
124 => [520, 318, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //2025
125 => [520, 418, 520, 520, 521, 521, 723, 723, 723, 823, 722, 722], //2026
126 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //2027
127 => [620, 419, 520, 419, 520, 521, 622, 722, 722, 823, 722, 621], //2028
128 => [520, 318, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //2029
129 => [520, 418, 520, 520, 521, 521, 723, 723, 723, 823, 722, 722], //2030
130 => [520, 419, 621, 520, 621, 621, 723, 823, 823, 823, 722, 722], //2031
131 => [620, 419, 520, 419, 520, 521, 622, 722, 722, 823, 722, 621], //2032
132 => [520, 318, 520, 420, 521, 521, 723, 723, 723, 823, 722, 721], //2033
133 => [520, 418, 520, 520, 521, 521, 723, 823, 723, 823, 722, 722], //2034
134 => [520, 419, 621, 520, 521, 621, 723, 723, 823, 823, 722, 722], //2035
135 => [620, 419, 520, 419, 520, 521, 622, 722, 722, 823, 722, 621], //2036
136 => [520, 318, 520, 420, 521, 521, 722, 723, 723, 823, 722, 721], //2037
137 => [520, 418, 520, 520, 521, 521, 723, 723, 723, 823, 722, 722], //2038
138 => [520, 419, 621, 520, 521, 621, 723, 723, 823, 823, 722, 722], //2039
139 => [620, 419, 520, 419, 520, 521, 622, 722, 722, 823, 722, 621], //2040
140 => [520, 318, 520, 420, 520, 521, 722, 723, 722, 823, 722, 721], //2041
141 => [520, 418, 520, 420, 521, 521, 723, 723, 723, 823, 722, 722], //2042
142 => [520, 419, 621, 520, 521, 621, 723, 723, 823, 823, 722, 722], //2043
143 => [620, 419, 520, 419, 520, 521, 622, 722, 722, 723, 722, 621], //2044
144 => [520, 318, 520, 419, 520, 521, 722, 723, 722, 823, 722, 721], //2045
145 => [520, 418, 520, 420, 521, 521, 722, 723, 723, 823, 722, 722], //2046
146 => [520, 419, 621, 520, 521, 621, 723, 723, 823, 823, 722, 722], //2047
147 => [620, 419, 520, 419, 520, 520, 622, 722, 722, 723, 721, 621], //2048
148 => [519, 318, 520, 520, 520, 521, 622, 722, 722, 823, 722, 721], //2049
149 => [520, 318, 520, 420, 521, 521, 722, 723, 823, 823, 722, 722] //2050
];
//节气名称
$term_name = [
'小寒', '大寒', '立春', '雨水', '惊蛰', '春分', '清明', '谷雨',
'立夏', '小满', '芒种', '夏至', '小暑', '大暑', '立秋', '处暑',
'白露', '秋分', '寒露', '霜降', '立冬', '小雪', '大雪', '冬至'];
//算取在数组中的位置
$line = $year - 1901;
$row = $month - 1;
//显示相应的节气
if ($day == substr($solar_term[$line][$row], 0, 1)) {
$term = $term_name[($month - 1) * 2];
} else if ($day == substr($solar_term[$line][$row], 1, 2)) {
$term = $term_name[($month - 1) * 2 + 1];
} else {//from www.feishuai.vip
$term = '';
}
return $term;
}示例：
echo getJieQi(1584652027);//春分