Ask Siri when the next prayer time is, and she will let you know which prayer is upcoming and how long you have until it’s due. 

It would be good to double check the accuracy for your region with another source just in case something is wrong. If it’s accurate once, then that should mean it will always be accurate! I just don’t want to give wrong information, but I’m pretty sure the prayer time info should be accurate (I used an API).