Calender planning

Question

If I want to repeat 37 different activites every 1,3,7, 21,45 & 60 days and no two activities can be done on the same day,what is the minimum number of days required?

Answer 1

One of the activities must be repeated every 60 days. 

So the minimum number of days required is 60!

Answer 2

One activity per day. So 37