I'm looking for an addon that will allow me to view and/or edit the ingame calander for any of my characters on any other character (ie edit my paladins calander on my warlock) any thoughts or suggestions?

In-game calendar requires security login (as it is account related and character specific).. You can only access it in-game or through wowarmoury after logging in with your account information..

I know i ment while in game i can view my other characters on the same account

http://wow.curse.com/downloads/wow-addons/details/group-calendar.aspx maybe?

Group Calendar would be the only way.. The in-game calendar is as far as I know, stored on Blizzard servers so while you are on one toon, you cannot access or see the info for another, even if they are on the same account..

you can invite your other chars to an event then promote them to assist so they can invite/edit stuff for that event
Other then that the only other way is for an addon that'll save your events on the calendar from one char and give the option to display them on another char however if these events/invites change it wont change untill you log onto that char and get the latest info from the calendar to save