The purpose of this Task workflow rule would be to email the user assigned to the Task when the "alert on days open" = the how many days the Task has still been open from Task Priority setup.
Select Tasks.TaskID, ezy_Users.FullName as PersonName, ezy_Users.Email, Tasks.Category, Tasks.Summary, @ICMID as ICMID
From Tasks INNER JOIN ezy_Users ON ezy_Users.UserID = Tasks.CreatedUserID
INNER JOIN Priorities ON Priorities.Priority = Tasks.Priority
INNER JOIN Status ON Status.Status = Tasks.Status
Where Status.Closed = 0
And Priorities.AlertOnDaysOpen > 0
And DateDiff(d, Tasks.CreatedDate, getdate()) >= Priorities.AlertOnDaysOpen
And ezy_Users.disabled = 0
and ezy_users.email is not null
And (Tasks.TaskID not in (Select TaskID From TaskChanges Where TaskChanges.TaskChangeMasterID = @ICMID))