I publish my changes but the site doesn't appear to be changing.

The most likely cause is a mix of UPPER/lower case letters in your filenames.
The file of: calendar.htm is different from Calendar.htm on a Linux-based system.
If you are trying to link to a page named "Calendar.htm" but the actual page is named "calendar.htm", "Calendar.html", or "calendar.html" your link won't work and the page won't be found.

Another possibility is that when you made your changes you accidentally created another copy of the web page you changed and the name is now different. Hence, your old page will continue to appear.

Be sure that you are always using all "lowercase" letters in your filenames. Files and the links that refer to them MUST be exact.