Not that you don’t trust your credit-card provider, or anything like that. But being familiar with the rules will help you know your rights and when a bank’s trying to pull a fast one.

Among the rules that kick in this week, there are five in particular that you’ll want to know about. Specifically, those rules state your provider must —

Send your billing statement at least 21 days before the billing date. No more getting the bill the day before it’s due. The old rule said providers had to give customers a “reasonable time” to pay the bill, but no one knew what a reasonable time was.

Credit you with on-time payments received the day after a weekend or holiday. Let’s say your due date falls on a Sunday, and the CC provider doesn’t get your payment until Monday. Previously, you’d get hit with late charges. No more.

Credit you with on-time payments received by 5:00 p.m. on the due date. This was hit or miss before. Providers pretty much could decide on a whim whether to hit you with a late charge for payments received at the end of the business day. You normally won’t want to wait until the last minute, but if you have to, consider using registered delivery to verify when the provider received the payment.

Give you 45 days’ notice on rate and penalty increases. Previously, the rules said the provider had to give you only 15 days’ notice. The new rules give you more time to switch cards if you don’t like the new rates.

Limit your rate increases only to new balances. So, if the provider does increase rates, the increase will apply only to new charges and not to existing balances.