To create a calendar that is only active during Peak and Standard times, the easiest is to start from a full TOU Calendar, and then fuse Peak and Standard Rates together.
You can clone a full TOU Calendar (e.g. Megaflex TOU) to a new Calendar, lets call it Megaflex Peak+STD by going to File->New->Calendar->TOU Calendar and using the 'Megaflex TOU' as the template.
After this, select the new 'Megaflex Peak+STD' Calendar and go to Edit->Calendar Rate Periods
Here, rename Standard to Peak+STD
Then go to Edit->Calendar Day Patterns and for every Day Pattern, where ever Peak is selected, just change it to Peak+STD
Then go back to Edit->Calendar Rate Periods and delete Peak. This will leave you with just Peak+STD and Off Peak
The rest of the calendar should stay the same.
You can now certify the calendar under Tools->Certify Calendar as Valid