As for calendar, I never had any problems with it. Of course it's not standard way that most people get used to, but I think any person will understand what to do.
When you face the choice, to hide a feature instead of removing it altogether can be a good compromise. So it can be still discovered casually, it can spread by the word of mouth, blog posts, and of course the user manual.
When selecting text, would you, for example, put select-word/select-line buttons everywhere a text can be selected or just let people discover what triple click does?
The topic is debatable, I just wanted to say that this kind of choice does make sense to me, and probably many others.
But I guess there is no easy way to accommodate for both those that do need 1-minute intervals and those who would rather have 5-minute intervals (without adding yet another UI element or yet another setting to toggle).