Can you pray two nine hour novenas almost simultaneously in one day?

[BigRon]

For example if you wanted to pray one on the hour for nine hours and a second one on the half hour for nine hours would this be okay or would it complicate things?

 

[Tis_Bearself]

You can pray how you want. Two in one day, two at the same time, etc.
There are no rules about personal prayer. The important thing is just that you pray, sincerely.

 

[OurLadyofSorrows]

For example if you wanted to pray one on the hour for nine hours and a second one on the half hour for nine hours would this be okay or would it complicate things?

It might be a good idea to speak with your Priest about why you are praying, and what your goals are.