Hey Jennifer,
This feed will respond with all the events a year from the date that it is requested. So, anything new that is added will be supplied when
However, if this URL is being supplied to another calendar for import, that system will need to continually request that information and have a way to import anything that is new from the previous import. For example, if importing via URL into Google Calendar, it does look like this request is handled automatically.
Let me know if this helps.
Thanks!