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HTML5-CSS-Calendar-Icon-HTML.html

<time datetime="2014-03-20" class="icon">
  <em>Thursday</em>
  <strong>March</strong>
  <span>20</span>
</time>

HTML5-CSS-Calendar-Icon-input.scss

// ----
// Sass (v3.3.3)
// Compass (v1.0.0.alpha.18)
// ----

$primary-color: #fd9f1b;

body {
  font-family: Helvetica, sans-serif;
}

time.icon {
  font-size: 1em;
  display: block;
  position: relative;
  width: 7em;
  height: 7em;
  background-color: #fff;
  margin: 2em auto;
  border-radius: 0.6em;
  box-shadow: 0 1px 0 #bdbdbd, 0 2px 0 #fff, 0 3px 0 #bdbdbd, 0 4px 0 #fff, 0 5px 0 #bdbdbd, 0 0 0 1px #bdbdbd;
  overflow: hidden;
  
  * {
    display: block;
    width: 100%;
    font-size: 1em;
    font-weight: bold;
    font-style: normal;
    text-align: center;
  }
  
  strong {
    position: absolute;
    top: 0;
    padding: 0.4em 0;
    color: #fff;
    background-color: $primary-color;
    border-bottom: 1px dashed darken($primary-color, 10%);
    box-shadow: 0 2px 0 $primary-color;
  }
  
  em {
    position: absolute;
    bottom: 0.3em;
    color: $primary-color;
  }
  
  span {
    width: 100%;
    font-size: 2.8em;
    letter-spacing: -0.05em;
    padding-top: 0.8em;
    color: #2f2f2f;
  }
}

HTML5-CSS-Calendar-Icon-output.css

body {
  font-family: Helvetica, sans-serif;
}

time.icon {
  font-size: 1em;
  display: block;
  position: relative;
  width: 7em;
  height: 7em;
  background-color: #fff;
  margin: 2em auto;
  border-radius: 0.6em;
  box-shadow: 0 1px 0 #bdbdbd, 0 2px 0 #fff, 0 3px 0 #bdbdbd, 0 4px 0 #fff, 0 5px 0 #bdbdbd, 0 0 0 1px #bdbdbd;
  overflow: hidden;
}
time.icon * {
  display: block;
  width: 100%;
  font-size: 1em;
  font-weight: bold;
  font-style: normal;
  text-align: center;
}
time.icon strong {
  position: absolute;
  top: 0;
  padding: 0.4em 0;
  color: #fff;
  background-color: #fd9f1b;
  border-bottom: 1px dashed #e38502;
  box-shadow: 0 2px 0 #fd9f1b;
}
time.icon em {
  position: absolute;
  bottom: 0.3em;
  color: #fd9f1b;
}
time.icon span {
  width: 100%;
  font-size: 2.8em;
  letter-spacing: -0.05em;
  padding-top: 0.8em;
  color: #2f2f2f;
}

HTML5-CSS-Calendar-Icon-rendered.html

<time datetime="2014-03-20" class="icon">
  <em>Thursday</em>
  <strong>March</strong>
  <span>20</span>
</time>