How do I add more to make the chart two weeks long vs. just one week

Also I would love to be able to update the days instead of having it written in how can I change that to a "pop up" calendar which switches the days in each box depending on the day you put in the first one to make the billing cycle complete .... since sometimes the billing cycle doesn't always start on a monday, so we don't have more emails than necessary and can change the form depending on the date. 

I apologize for not understanding your request. Could you please provide us with more information on what you would like to achieve and which fields you would like to alter, so we can inspect and assist you better?

Thank you in advance.