After filing Form N-400, Application for Naturalization, the entire naturalization process can take anywhere from 5-8 months. This is an approximation. It may be shorter for some and longer for others.
Best Answer Thanks! I assume from your question that you have a court order for child support that ordered your ex to pay the $820 per month. Assuming this to be the case, and assuming that the court did not allow your ex to reduce his payment, you can go back 10 years to collect arrearages.
You asked whether a person can get a modification of a child support order that is nearly 20 years old to increase the time period for paying child support by requiring payment until the child reaches an age beyond the age specified in the original order.