How does one create an alarm for the day it is set. In other words, I want it to sound today and I don’t want it to repeat.

How does one create an alarm for only the day it is set? In other words, I want the alarm to sound today and I don’t want it to repeat.

Currently, I set the alarm and then make sure to check whatever day of the week it is to make sure the alarm will sound today. I worry that if I don’t check the day then it won’t sound at all. Is that correct? Or is it as simple as I simply need to not check any of the days?