How Many Days

Living in Basel, I need to learn German.  Today, I can proudly announce a 210-day German learning streak on DuoLingo (a language learning App).  That's 210/365 of a whole year! Applause accepted.  Now 210/365 can be simplified to a not very simple 42/73, but my question is: 

In how many days could my efforts be simplified to a fraction where both numerator and denominator are single digits? 

Think you've got the answer? Check it here

First solved in Switzerland by Dimitrios

First solved in the US by Olympia