How to change balloonText in amchart

I'm using real time amchart and I want to add date to the balloonText, this is the code:

 "balloonText": "<img src='javascripts/images/info.png' style='vertical-align:bottom; margin-right: 5px; width:28px; height:21px;'><span style='font-size:14px; color:#000000;'><b>[[value]]</b></span><img src='javascripts/images/time.png' style='vertical-align:bottom; margin-right: 5px; width:28px; height:21px;'><span style='font-size:14px; color:#000000;'><b>[[category]]</b></span>",

I want to add today's date next to [[category]], how? Thank you.