For many years, I've been subscribing to calendars to keep track of events, mostly sporting events. When you subscribe to a calendar, it doesn't add events to your main calendar. Instead it adds a new calendar in addition to your main calendar. All events on that new calendar are loaded dynamically on a regular basis from the source.
For example, when you subscribe to a baseball team's schedule, each game appears on the calendar automatically. If there are post season games, those will also appear automatically. Many sports teams also add scores at the end of games, so you can look back at any past game to see the result.
For purposes of these instructions, I will use Google Calendar in my examples. I'm using the Chrome browser on my desktop computer. I'll address mobile devices later. Also, the actual calendar examples will be of interest to people who live in or near De Pere, Wisconsin.
So, let's get right to our first example, and subscribe to a calendar.
1) In Google Calendar, in the left column, click the small plus sign above "My calendars", and select "From URL".
2) Paste the URL to a calendar. Let's start with the Green Bay Packers schedule, so paste this URL: https://www.southendzone.com/ical/packers.ics
3) Click "ADD CALENDAR".
That's it. Three simple steps to subscribe to a new calendar. All you need is the URL of the calendar for step 2 above.
You'll now see a calendar on the left named "Green Bay Packers". You can turn it on and off with the checkbox next to the name. You can also click the three dots to the right of the calendar to change the color of its events. Look at past games on your calendar to see the score.
To subscribe to any calendar, you need to find the URL on the web page. Sometimes it's called the iCal URL. Here are the URLs of some calendars that you may be interested in. To use one, just copy it and paste it in step 2 above.
De Pere High School Calendar
West De Pere High School Calendar
Bay Conference Football Schedule
Fox River Classic Conference Football Schedule
Wisconsin Badgers Football Schedule
Green Bay Packers Schedule
You can also subscribe to calendars on your smartphone or tablet. However, in my many years of developing and working with calendars, I've found that smartphones aren't always good at calendar subscriptions. iPhones and Macs seem to have the most trouble. So, in order to subscribe to a calendar on your phone, my best suggestion is to first do it in your Google accont as I've described above. Then setup your phone to sync with that same account, which will also cause all calendar data to sync as well.
If you're looking for a good Android calendar, I strongly recommend Calengoo. It syncs with your Google Calendar, and it allows you to select which calendars you want to display on your phone. The Google Calendar app is also very good, on both Android and iOS devices.