It's all Inevitable!
Path to inevitability...

CntTagBot version history
This 1.5 native plugin add simple things (Demo):

Day counter:
{ctb|daycnt|to/since|year|month|day} - replaces the tag with the number of days to or since the specified date.

Under construction tag:
{ctb|cnstr|message} - replaces the tag with a "Under construction message", with a central and instance unique text.

Version 1.0 (19feb2009) - First version that solved my own initial needs.

Click on the versionUrls above to download.