this is exactly what it says: 

CHANGE PROFILE NAME

Oh no! You can only change your name every 30 days.

Your last name change was on 3/30/2021. You can change it again in 0 days.

I know that might mean today but it would be helpful if it says the hour of when you can change your Minecraft username. So I know exactly when to log in and change the username. Thank You!

(i put a screenshot of the problem)