php

$date = [
    '2019-12-31 12:22:33',
    '2019-11-10 12:22:22',
    '2018-12-01 12:22:33',
    '2019-05-11 11:11:11'
];

$now = time();

function getNearDate($date, $com){
    $cnt = count($date);  
    if ($cnt === 0) return false;
    for($i=0 ; $i < $cnt; $i++){
        if(isset($date[$i+1])) {           
            $front = abs($com - strtotime($date[$i]));
            $behind = abs($com - strtotime($date[$i+1]));          
            if($front < $behind) {
                list($date[$i], $date[$i+1]) = [$date[$i+1], $date[$i]];
            }
        }
    }

    return end($date);
}

var_dump(getNearDate($date, $now));

golang

package main

import (
    "fmt"
    "time"
    "errors"
)

func main() {
    arr := [] string { 
        "2019-12-31 12:22:33",
        "2019-11-10 12:22:22",
        "2018-12-01 12:22:33",
        "2019-05-11 11:11:11"}
        

    now := time.Now().Unix()

    res, err := getNearDate(arr, now)
    if err != nil {
        panic(err)
    }

    fmt.Println(res)
}

func getNearDate(date_arr []string, timestamp int64) (string,error) {
    
    cnt := len(date_arr)
    if cnt == 0 {
        return "输入非法",errors.New("输入非法")
    }

    for i:=0; i<cnt;i++ {
        if i < cnt-1 {
            before := Int64abs(timestamp - strtotime(date_arr[i]))
            behind := Int64abs(timestamp - strtotime(date_arr[i+1]))
            if before < behind {
                temp := date_arr[i]
                date_arr[i] = date_arr[i+1]
                date_arr[i+1] = temp
            }
        }
    }

    return date_arr[cnt-1],nil
}

func strtotime(date string) int64 {

    timeLayout := "2006-01-02 15:04:05"                           
    loc, _ := time.LoadLocation("Local")                            
    theTime, _ := time.ParseInLocation(timeLayout, date, loc) 
    sr := theTime.Unix()                                          
    return sr
}

func Int64abs (num int64) int64 {
    if num < 0 {
        return -num
    }
    return num
}