Step 1: Go the specific calendar view that you would like to appear when the link is clicked.

Step 2: Paste the link into an editor like Word or Notepad.

Step 3: Find the area in the link that shows something like: oc_id[]=1005 (Note: You may have multiple oc_id's.  If so, just find the last one.)

Step 4: Delete everything after the number.

Step 5: Delete everything before the "/modules/" text.

Step 6: From the Top or Side Navigation, use the "Link to an External page"  option.   In the Link URL box, paste the path to the file (overwrite the http://).

Example

Original link:
http://school.groupfusion.net/modules/calendar/showCalendarMonth.phtml?com=t&oc_id[]=1005&sessionid=cc9f90d9a236cc638a509581eb4b6bed&sessionid=cc9f90d9a236cc638a509581eb4b6bed

Pasted link:
/modules/calendar/showCalendarMonth.phtml?com=t&oc_id[]=1005