Иконка календарь с помощью CSS3

* { 
  margin: 0; 
  padding: 0; 
} 
 
.icon { 
  display: inline-block; 
  width: 40px; 
  padding-top: 34px; 
  border: 1px solid #222; 
  margin-top: 30px; 
  margin-left: 30px; 
  position: relative; 
} 
 
.top-line { 
  background: #222; 
  width: 40px; 
  height: 16px; 
  position: absolute; 
  top: 0px; 
  text-align: center; 
} 
 
.top-line span { 
  display: inline-block; 
  width: 5px; 
  height: 10px; 
  background: #666; 
  transform: translate(0, -10px); 
  box-sizing: border-box; 
}

<div class="icon"> 
  <div class="top-line"> 
    <span></span> 
    <span></span> 
    <span></span> 
    <span></span> 
  </div> 
</div>