Missing live events (like press conferences) on the Canadian Broadcasting Corporation's website cbc.ca is a very easy thing to do because they are not scheduled very far in advance.  Usually live events appear all of a sudden in the cbc's video section, and then they disappear without a trace afterwards.  There is no way to know that a potentially important live event is happening.

This tool shows a notification on-screen when live video events happen on cbc.ca.  When the notification pops up, click on "Start Streaming" to open the live stream in the web browser.

Unfortunately the CBC will only stream content to computers in Canada.
