I am using Revenuecat for flutter. During package subscription I want to give certain discount to the users while purchasing. Is there any way to give discount from client side on package subscription?
You can use iOS subscription offers, or iOS offer codes, and Android promo codes which are not exactly what you want.
As far as I know, Apple and Google subscriptions are period based (monthly/yearly) only, compared to calendar based ("subscribe for this year").
What I would do is create a subscription offer that last a certain number of months and after those months it becomes full price. The certain number of months (and the offer price) depends on how far you are in the year.