String 617 not clear to me

[Hannie Dumoleyn]

I have some trouble translating the following string:
A built in calendar application called <app>Calendar</app> allows you to 
organize your calendar appointments or events. Up to five of these, over 
a four-week duration, will appear by clicking on the clock in the 
<gui>menu bar</gui>.

What is meant by "up to five of these" and "over a four-week duration"? 
Five calendars?
When I click on the clock, I see this month, April 2016. Each time I 
click on the left/right arrows I can go back or forward one month or 
year. But I can do this more than five times.

Hannie