The script to tasks EasySocial groups

I did so the tasks and assignments for users created only the author or admin of a group. The user installs the application tasks for yourself. And it displays tasks created by the author group. The user cannot change the task status (to delete or mark as performed). The function to create new tasks for user I removed. There's a good application - Calendar. In the task I changed the appearance of added time to complete the task. But if the author of the group, when the job is created do not specify time for the task is added - "Due on -0001-11-30"
1. How to do to add "-" instead "-0001-11-30"
2. How to make a link to the task so that the user can open the task.

If anyone is interested, I could upload algorithm changes. You could make a patch for users.