In his article The Era of Symbol Fonts, Brian Suda refers to
Timepiece Rounded, an OpenType font that makes use of the symbol font concept and specifically ligatures to display clock hands!
For instance, a time string such as “19:52:45” will be displayed as follows:
The source code for this contains merely text and and a bit of CSS styling:
<div class="timepiece missswiss"><span class="clock" id="missswiss" style="display: block; font-size: 226px;">19:52:45</span></div>