title: Data persist in redis even after prescribed timestamp
body: <p>I'm building a chatroom cache which should persist for 2 min in redis database, but even after using expireat method cache does not get cleared.</p>
  <p>This is my code for storing the cache</p>
  <pre><code>//check whether room already exists or not
  //if not set certain expiry timestamp 
  
  client.lrange(room,0,-1,async(err,replies)=&gt;{
      console.log(err,replies)
      if(replies.length==0)
        {
          const when = 2*60
          client.set(room,[],'EX',when,(err,ans)=&gt;{//here in seconds
                 console.log(`setting expiry at ${ new Date(Date.now() + when*1000)}`) //here in milliseconds 
          })
        }
    })
  
  //push the messages into room list at redis 
  await client.rpush(room,`${from}:${message}`);
  </code></pre>
  <p>But even after desired timestamp is passed messages continue to persist.
  I will be more than grateful if somebody guides me.
  Thank you in advanced!</p>