I’ve done this before and I though immediately of editing the web part to change that, but it turns out that wasn’t the right choice. It took me about five minutes of digging after getting off the call to figure out where to make the change and I wanted to share this with everyone.
Here is what the customer saw:
And here is what she wanted to see:
The way to change this is to log into PWA as an administrator and go to Server Settings > Task Settings and Display.
Next, change the Reporting Display value from “Resources should report their total hours worked for a week” to the other option.
Save your changes and the views in My Tasks will be updated so users can enter Actual Work by Day rather than by Week. This same change can be done in Project Server 2010's PWA.