NovaT6 defines the block to be scheduled with a shape of doubles/singles just big enough to accommodate the doubles/singles you have specified.
For example, if you say each Y7 class has 3 doubles and 6 singles, the default shape of the linear block calculated by NovaT6 would be 3 doubles & 6 singles. That obviously forces all the doubles to be on at the same time.
If you change the shape of the linear block from 3 doubles and 6 singles to 6 doubles, then NovaT6 would be able to put the doubles anywhere in the block.
The shape of the block is defined in the Sessions tab. Click on the icon 'Block' and enter the new shape.
As I usually schedule linear blocks last, I usually calculate the shape of the linear block to have the maximum possible number of doubles that will fit, taking into account hard breaks, lunch, etc. Any odd periods will obviously be singles.
Hope this helps.
