Bootstrap, progress bar

Bootstrap, progress bar

Hello to everyone.

I use boostrap and one of his component is progress bar: 

  1. <div class="progress progress-striped active">
      
    <div class="bar" style="width: 40%;"></div>
    </div>     
width: 40% are our progress, what we can see.

So, how can i force work progress bar? I want to put date somewhere in code, and then watch, how my progress bar moving. Please prompt me, what i need to write, thanks.