ICal is just the old name for what is currently Apple's main 'Calendar' application (referenced ). They are exactly the same thing, Apple just rebranded iCal a few years ago. That being said, there is a relatively easy (albeit lengthy) way to go about putting an Excel file into the Calendar app. Essentially you have to export the Excel document as a CSV, and then change it into an.ics format in order to get it to work.
Instead of trying to repeat what I have found, is the original article (updated as of 2013) which says it much better than I can in this small space.
You can also use a pre-built calendar template in Excel, with the calendar already formatted for you. There a variety of pre-built calendar templates for Excel, ranging from 12-month calendars, monthly calendars, weekday displays, and calendars with notes.
For your security & protection WinCalendar is hosted on CNET's Download.com.