WooCommerce - Bill product partial time of the month

Before explaining, we want to be very clear that we're a Web Agency and we're looking for long term providers that are affordable and also very experienced with lots of years working on hosting environments / very experts in WooCommerce in this case. Very honest people, if you do this fine we will give you more tasks of other projects, since we're an agency and have multiple clients / projects, most of them based in WordPress and WooCommerce. So we're still looking for a coder that is honest and make things fast with reasonable prices and also that bills us by minutes. == General requirements for any freelancer in this kind of tasks - Have a good english (we also talk portuguese and spanish, just in case you use any of this languages). - Available to talk via voice in some special cases, where explain is 10x times faster than wriing down. - Better if you're a WordPress coder / developer - Available for long term deals and other future projects - We want freelancers that fixes issues in minutes, not in hours. At least 10 years experience per area. - We want you to bill us in minutes, since we will give you multiple tasks on same or different projects, then would be good to make a monthly payment or maybe make prepayment hours. All this if you show us u're good, of course. == Tasks for today We are going to start a web with Wordpress and Woocommerce. We want to sell only 2 products that will be the modalities of registration in the gym. We need woocommerce to charge each product: Fixed price of the registration + days remaining until the end of the month. Example: Price of the registration = € 100 Price of the monthly payment = € 30 If the client hires on the 12th, he will have to pay: Registration fee (€ 100) + 18 days to finish the month (€ 18) It must be able to be done with a Plugin or with a solution that allows to modify it in a simple way..