Steve Mosen

Displays the number of days until/after a specified date. Example: [kit-days-away day=25 month=12 year=2012]

Days Away

Displays the number of days until/after a specified date.

dmonnier

A fully CSS-able jQuery countdown/countup timer available in both widget and shortcode. Based on <a href="http://keith-wood.name/countdown.html" title="jQuery Countdown by Keith Wood" rel="nofollow ugc">jQuery Countdown</a> by Keith Wood.
Features:
<ul>
<li>Supports multiple countdowns</li>
<li>Available as both a widget and a shortcode</li>
<li>Localization based on your WordPress’s installation language</li>
<li>Timer can be set to count down or count up</li>
<li>You choose how much information to display from years to seconds</li>
<li>Option to set expiration message</li>
<li>Option to redirect to a new URL upon expiry</li>
</ul>
Most importantly, YOU have full control over the CSS! Every single element can be targeted and manipulated any way you want. Also works right out of the box with four pre-defined display styles if you don’t care to fiddle with the CSS yourself.
<h3>Future Development</h3>
<ul>
<li>Pre-built color schemes</li>
<li>Upgrade to version 2.0.0</li>
<li>Admin panel localization</li>
</ul>

CSSable Countdown

A fully CSS-able jQuery countdown/countup timer available in both widget and shortcode.

Days Away vs CSSable Countdown