> As an end user I would assume that if I switched from a special schedule to a normal schedule, Puppet should wipe the special schedule entirely.

Lots of discussion on that in [3010](http://projects.puppetlabs.com/issues/3010). Allowing a special schedule to be removed via `special => absent` was the smallest change that will improve the situation. This fix could attempt to do more if there are no backwards compatibility concerns.

> If both a special schedule and normal schedule parameters are specified the resource should fail to validate, otherwise we shouldn't require special casing like that.

Issue [4820](http://projects.puppetlabs.com/issues/4820). Seems like we should at least kick up a warning in this situation---an error if changing the behavior to failure isn't another compatibility concern.