根据日期查询节气：
function get_jie_qi()
{
$_year = 2023;
$month = 5;
$day = 21;
$year = substr($_year, -2) + 0;
$coefficient = array(
array(5.4055, 2019, -1),//小寒
array(20.12, 2082, 1),//大寒
array(3.87),//立春
array(18.74, 2026, -1),//雨水
array(5.63),//惊蛰
array(20.646, 2084, 1),//春分
array(4.81),//清明
array(20.1),//谷雨
array(5.52, 1911, 1),//立夏
array(21.04, 2008, 1),//小满
array(5.678, 1902, 1),//芒种
array(21.37, 1928, 1),//夏至
array(7.108, 2016, 1),//小暑
array(22.83, 1922, 1),//大暑
array(7.5, 2002, 1),//立秋
array(23.13),//处暑
array(7.646, 1927, 1),//白露
array(23.042, 1942, 1),//秋分
array(8.318),//寒露
array(23.438, 2089, 1),//霜降
array(7.438, 2089, 1),//立冬
array(22.36, 1978, 1),//小雪
array(7.18, 1954, 1),//大雪
array(21.94, 2021, -1)//冬至
);
$term_name = array(
"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");
$idx1 = ($month - 1) * 2;
$_leap_value = floor(($year - 1) / 4);
$day1 = floor($year * 0.2422 + $coefficient[$idx1][0]) - $_leap_value;
if (isset($coefficient[$idx1][1]) && $coefficient[$idx1][1] == $_year) $day1 += $coefficient[$idx1][2];
$day2 = floor($year * 0.2422 + $coefficient[$idx1 + 1][0]) - $_leap_value;
if (isset($coefficient[$idx1 + 1][1]) && $coefficient[$idx1 + 1][1] == $_year) $day1 += $coefficient[$idx1 + 1][2];
//echo __FILE__.'->'.__LINE__.' $day1='.$day1,',$day2='.$day2.'<br/>'.chr(10);
$data = array();
if ($day < $day1) {
$data['name1'] = $term_name[$idx1 - 1];
$data['name2'] = $term_name[$idx1 - 1] . '后';
} else if ($day == $day1) {
$data['name1'] = $term_name[$idx1];
$data['name2'] = $term_name[$idx1];
} else if ($day > $day1 && $day < $day2) {
$data['name1'] = $term_name[$idx1];
$data['name2'] = $term_name[$idx1] . '后';
} else if ($day == $day2) {
$data['name1'] = $term_name[$idx1 + 1];
$data['name2'] = $term_name[$idx1 + 1];
} else if ($day > $day2) {
$data['name1'] = $term_name[$idx1 + 1];
$data['name2'] = $term_name[$idx1 + 1] . '后';
}
echo json_encode($data,JSON_UNESCAPED_UNICODE);
}输出：
{"name1": "小满","name2": "小满"}