How to filter list of active clients in a given period [closed]

Good morning, everyone. I am developing a management software for a home care company. I have a list of clients that may be active or inactive within a given month. Each customer has a contract value with the company and costs it generates each month. To calculate the net profit of the company within a given month I generated one scaffold per month. I need every month to get the list of active clients in that period, how can I do this? A query to clients with condition = active within a certain period? Thanks to anyone who can help.