Hi,

The last Calendar type in MS PROJECT 2010 is the Task Calendar. Remember this: If you have the Project Calendar, and the Resource Calendar (or Calendars), and the Task Calendar, TASK CALENDAR HAS PRECEDANCE!

Why do you need a Task Calendar. I will give you an example on our “Wedding” Project. We do not know when will we have a wedding. We are still in a Planning phase. But what we DO KNOW that the wedding will start at Saturday, and it will finish on Sunday. We do not know WHICH Saturday and Sunday, but we know that the wedding will be on this two days.

When you need specific Task Calendar, DO NOT use and modify standard Calendars. Create your own, instead. Why? Because if you modify working time on the Standard Calendar, and you use it with different tasks and different resources, you can get unpredictable results. Here is an example. If I modify standard Calendar in MS PROJECT 2010 and if I put the work time only at Saturday and Sunday, all my tasks will be scheduled to be conducted at these days.

I will now create the two brand-new calendars, and I will name it: “Wedding Saturday” and “Wedding Sunday”:

No I will remove all exceptions from my Calendar:

I will select all Exceptions and I will click on the Delete Button:

Now, I will set up Work Weeks. First I will delete the Specific work from 16.08.2011 to 31.08.2011. This specific work came from my previous posts, about Calendars, remember?:

Finally I will set up working and nonworking days for my Calendar:

and then:

DO NOT CLICK ON THE OK BUTTON! If you try you will get:

Why? Because I set up nonworking days from Monday to Friday, and Saturday and Sunday are nonworking days by default, it will means that you have Calendar without single working day, and that is seamless.

You can see that there will be no activities from Monday to Friday. But, on Saturday I will set up working time for 08:00 to 24:00 (e.g. 00:00, you can not put 24:00):

O.K. When will the wedding finish? At Sunday. But if it will start on Saturday it will keep going on Sunday. So I will make Wedding Sunday Calendar, as a copy of Wedding Saturday Calendar:

I will set up working time as a whole day:

and then:

That is it!

Now I will assign specific Calendar to the Specific Task(s).

and I will get:

You will notice that I made a mistake, but I did it purposely, and I will correct it when I will establish a schedule, later in my project (not in this post, of course). What is the Mistake? Well, look at a “Have a party” Task. The wedding ceremony will finish, for example, at 18:00 at Saturday, and then the party will start. But it will certainly not finish at Saturday. So this is the mistake. But, as I said, I will correct the mistake latter.

Now, suppose that I have a “Wedding couple” as a Resource with Standard Calendar:

I will assign that resource to the “Get Married” Task:

If I want to move out of this field I will get a warning message:

WHY? Well our “Wedding Couple” Resource has a Standard Calendar assign to them, and it Means they are available only at working days (Monday to Friday). One the other hand, the “Get Married” task has a “Wedding Saturday” Calendar and it will be conducted at Saturday. So we have a conflict, because our “Wedding Couple” are not available at their own wedding!!! . How to solve this conflict? Easy!

Double click on the Task and then choose:

With “Scheduling ignores Resource calendars” you are avoiding those types of conflicts in MS PROJECT 2010, because MS Project assume, that any resource will be available to my task if it has its own Calendar!

Best Regards!