After installation use the shortcode [timed] around any post or page contents that you wish to appear or expire on a specific date and/or time.
Six parameters can be used - ondate, offdate, ontime, offtime, onday and offday.
ondate : Date after which you wish the content to appear, in format YYYYMMDD. offdate : Date after which you wish the content to expire, in format YYYYMMDD. ontime : Time after which you wish the content to appear, in format HHMM. offtime : Time after which you wish the content to expire, in format HHMM. onday : Day on which you wish the content to appear - 1 (for Monday) through 7 (for Sunday) offday : Day on which you wish the content to expire - 1 (for Monday) through 7 (for Sunday)If any of these aren't specified then a logical alternative is found - e.g. not specifying ondate or ontime means the text will appear immediately (until the conditions of any expiry date/time is met).
Here's some examples of use..
[timed offdate="20122412"]It's nearly Christmas![/timed]
This will cause the message to disappear after the 24th December 2012.
[timed ondate="20120101" offdate="20121231"]It's 2012[/timed]
This will cause the message to only appear during the year 2012.
[timed ondate="20120101" offdate="20121231" ontime="0800" offtime="1200"]It's between 8am and midday[/timed]
This will cause the message to appear between 8am and midday during the year 2012.
[timed onday="1" offday="3"]It's Monday to Wednesday[/timed]
This will cause the message to only appear Monday, Tuesday and Wednesday.