We have multiple calendars as well - for Blogs, Emails, etc. But, we do have to keep in mind the potential changing of dates, as David mentions. For example, our settings on the calendar indicate:
On the calendar, show: End Date Only
When Actual dates aren't available, show: Planned dates
(Our filters for the calendar are based on Projects.)
Blog Calendar Example:
The last task on the project is the same date as the Planned Completion Date (the date of the blog posting). So, let's say on the Blog Calendar, we have a blog post scheduled for August 17 - on the Calendar this shows up on August 17. This is good in that it shows on the calendar the blog posts we have planned. However, if the person assigned on the last task marks their task Complete on August 20 (even though the blog post was posted on August 17), then that blog post now appears on the Calendar on August 20, because now there is an Actual Date.
The majority of the time those last tasks are done on the day, but there are some occasions where the project 'moves' on the calendar. I agree with David, if there was the ability just to keep planned dates only, it would be great! Terry Hynd EBSCO Information Services