James Golovich

<a href="http://www.woothemes.com/woocommerce/" rel="nofollow ugc">WooCommerce</a> doesn’t remove an item from inventory until someone actually buys 
that item. This plugin can reduce the “virtual” stock quantity of an item without actually modifying the item 
inventory, so there should be no problems with missing data if somehow the cart data is deleted. This plugin isn’t for 
everyone, but people that are selling specialty items will find it useful and hopefully eliminate some customer 
support nightmares.
The plugin can automatically expire items from the cart (disabled by default) with a configurable expiration time. 
Expiration times are plain english using whatever types php’s strtotime can support (Examples: 10 minutes, 1 hour, 6 hours, 1 day) 
Per item expiration time can be configured by adding a Custom Field to each item using the configured 
‘Expire Custom Key’ (default name is ‘csr_expire_time’).
Expiration can be enabled independently of reducing the cart stock, so this plugin can also be used to expire items at 
other intervals than the default WooCommerce cart/session expiration.
An issue was opened on the <a href="https://github.com/woothemes/woocommerce/issues/5966" rel="nofollow ugc">WooCommerce issue tracker</a> regarding 
this problem and someone posted on Facebook about it, which caught my attention.
Please submit bug reports, feature requests, and pull requests via the <a href="https://github.com/jamesgol/woocommerce-cart-stock-reducer" rel="nofollow ugc">GitHub repository</a>
<h3>TODO</h3>
<ul>
<li>Look into adding ajax and mini-cart notices</li>
<li>Take some screenshots for wordpress.org</li>
<li>Add some kind of indicator to cart so you know what items will expire</li>
</ul>
<h3>Thanks</h3>
<ul>
<li>Bob DeYoung of <a href="https://github.com/bluelotusworks" rel="nofollow ugc">BlueLotusWorks</a> for testing, feedback, and support</li>
</ul>

WooCommerce Cart Stock Reducer

I use both virtual stock reduction and cart item expiration. Both work exactly as promised.

I was also able to:
1. Add a "Quantity reserved" column to my product list in admin
2. Localize the countdown text for cart expiration
thanks to the excellent code in thus plugin.

Just fantastic - a must at sometimes busy stores

We needed a ticket-sales like cart capability where a ticket is 'blocked' once added to a cart preventing others from purchasing for a set-time, but then needed to return the item to the cart automatically after the timeout.

This plug-in worked perfectly with the latest Woo Commerce plugin, additionally displaying a count-down timer nicely in the cart. When the timer expires the item is removed from the cart automatically.  

Nice work!

Using for a cart-timer so that items return to inventory after timeout

Allow WooCommerce inventory stock to be reduced when adding items to cart and/or expire items from the cart

TIEro

This plugin is now part of the free plugin <a href="https://wordpress.org/plugins/tietools-automatic-maintenance-kit/" title="TIEtools" rel="ugc">TIEtools</a>, which also includes duplicate post control and server log file removal.
Simple post expiration plugin. Expires posts based on a variety of criteria, including category and post status options.
<ul>
<li>Expires published, draft, pending and private posts on demand.</li>
<li>Includes or excludes user-defined list of categories.</li>
<li>Moves all expired posts to the Trash.</li>
<li>Notifies post author, site admin and others of post expiry on demand.</li>
<li>Permanent post deletion is handled by WP’s built-in Trash removal.</li>
<li>Completely automated by wp-cron once options are set.</li>
</ul>
Currently, the plugin offers four cumulative expiration methods:
<ol>
<li>Expire posts based on their age (e.g. expire posts created more than 90 days ago).</li>
<li>Retain a given number of posts and expire all others (e.g. keep the latest 1,500 posts).</li>
<li>Detect the BAW Post Views Count plugin and expire posts based on a combination of post age and number of views (e.g. expire all posts over 45 days old which have fewer than 100 views).</li>
<li>Detect the WTI Like Post plugin and expire posts based on a combination of post age and total number of likes (e.g. expire all posts over 90 days old which have fewer than 10 likes).</li>
</ol>
Each expiration check is run separately and in the order listed above, so you can build quite complex expiration structures to catch a variety of criteria.
Post status choices apply to all expiration methods. The user-defined category filters can be switched on or off for each method.

TIEexpire Automated Post Expiry

Expires posts based on multiple criteria, with category and post status options. Sends notifications to users and admin on demand.

WooCommerce Cart Stock Reducer vs TIEexpire Automated Post Expiry