yes, these are from spiders, thanks for noting. Sometimes having an overly verbose package like xowiki has some advantages...
The problem is now fixed for xowiki in CVS HEAD and on www.openacs.org by specifying the offered time range for the weblog-mini-calendar from 2006 (birth of xowiki) to 1 year into the future from the actual date.
The problem exists as well for the link to the past as for link to the future. Adding two parameters for every calendar instance in openacs/dotlrn seems quite heavy, but in the general case, we don't have much options...
