Is it necessary to take sugar pills?

You can, but it kinda defeats the purpose of them. They're only there to help you develop a regular habit, like:

• get up
• go to the bath room
• take the pill
• continue with the day

The theory is that this will make it easier to remember taking the "real" pills at the right time.

Now, if you deliberately start taking the pills at different times, you're not setting the habit, and you run a greater risk of forgetting to take them.