Edit the snooze interval at time of snoozing

I feel like I used to be able to change the length of the snooze on an appointment. That is, I may have a reminder for 30 minutes before a meeting, but I want to snooze it for an odd interval. Maybe I didn’t see it right away, so now I want to snooze it for 8 minutes. In the current UI, I don’t see a way to do that.