JS countdown, how much time is left before a certain date?

The code is as follows:

& lt span? Id = "show"> loading ... & lt/span>.

& lt script? type = " text/JavaScript " & gt；

//time_val？ Compare time? Format: 2016-12-14? 22:55:40

Function? Countdown (time value) {

var？ www_qsyz_net=/^[\d]{4}-[\d]{ 1,2}-[\d]{ 1,2}(？ [\d]{ 1，2}:[\d]{ 1，2}(:[\d]{ 1，2})？ )? $/ig，str= ' '，conn，s；

If (! time_val.match(www_qsyz_net)){

Alert ('parameter format is 2012-01-01[? 01:01[:01]]. \ r [] can be omitted');

Return? Fake;

}

var？ Sec= (new? Date(time_val.replace(/-/ig，'/'))。 getTime()？ -? New? Date (). getTime())/ 1000；

If (seconds? & gt？ 0){

conn= '？ "Then what?";

} Otherwise {

conn= '？ "Has it passed?";

sec * =- 1；

}

S={' days': sec/24/3600，' hours': sec/3600%24，' minutes': sec/60%60，' seconds ':sec % 60 }；

For (me? Are you online? s){

if(math . floor(s[I])& gt； 0? )? str？ +=? Math.floor(s[i])？ +? Me;

}

if(Math.floor(sec)==0){？ Str = "0 seconds"; ? }

document.getElementById('show ')。 innerHTML？ =? Distance? & ltu & gt？ +? time_val？ +? '& lt/u & gt； ? +? Kang En? +' & lt； u & gt？ +? str？ +? '& lt/u & gt； ;

//Update once every second

setTimeout(function(){ count down(time _ val)}， 1000)；

}

Countdown ('2016-12-14? 22:55:40');

& lt/script & gt；