Why can't I create a Garmin Run Coach plan for a race that is happening soon?

Garmin run coach won't let me create a training plan for a half-marathon unless the event is 45+ days from now. Why?

This is a needless restriction that really limits the usefulness of the app. I should be able to create a plan for anytime I want, and shouldn't be forced to plan 45 days ahead.

I'd prefer getting an imperfect plan versus not being able to generate one at all. For example, if I generate a plan for a race 7 days from today, the app could just drop me into "day 38" of the 45 day training plan.