Add to Calendar
Create a button on a web page to add an event to any calendar
Create the event in a Google Calendar
Edit the event
Scroll to the bottom of the page. Below the Visibility section, click on Publish Event
A dialog will open with HTML code to copy and paste to your webpage. (See example below.)
Examples of buttons on a web page to add an event to Google Calendar
HTML Code
<a href="https://www.google.com/calendar/event?action=TEMPLATE&tmeid=MHAyMWlnMWduZXZoZTVsc2hsYm85NmFvZzAgc3N0eC5vcmdfYXA1YTdncWwxbmNmcmwwamRlZWxxdXVhaWdAZw&tmsrc=sstx.org_ap5a7gql1ncfrl0jdeelquuaig%40group.calendar.google.com" target="_blank"><img border="0" src="https://www.google.com/calendar/images/ext/gc_button6_en.gif"></a>
All six button options (non-working examples)
To select a button, change the name of the image near the end of the HTML code above - change gc_button6_en.gif to gc_buttonX_en.gif
Subscribe to a calendar
(either a public calendar or one that you have rights to through Group membership)
You can offer users an easy way to subscribe to a calendar (that is, for the user to add a calendar to the Google Calendars page).
HTML Code
<a href="http://www.google.com/calendar/render?cid=http%3A%2F%2Fwww.google.com%2Fcalendar%2Ffeeds%2Fsstx.org_siq5ectrvg921eipq0qdu5fho4%2540group.calendar.google.com
%2Fpublic%2Fbasic" style="line-height:21px;font-size:1em" target="_blank">
<img border="0" src="//www.google.com/calendar/images/ext/gc_button1.gif">
</a></div>
Get the calendar ID (in bold above) from the calendar's Settings page.