$h = date('H');
if ($h < 6) {
    $time = "凌晨好！";
} else if ($h < 9) {
    $time = "早上好！";
} else if ($h < 12) {
    $time = "上午好！";
} else if ($h < 14) {
    $time = "中午好！";
} else if ($h < 17) {
    $time = "下午好！";
} else if ($h < 19) {
    $time = "傍晚好！";
} else if ($h < 22) {
    $time = "晚上好！";
} else {
    $time = "深夜好！";
}