Tripit ical feed not updating
However, this also has the nice side effect that all old itineraries are retained.
Purpose: This property specifies a URL from where the calendar data was retrieved or where it can be refreshed.
Description: This property specifies a positive duration that gives a suggested minimum polling interval for checking for updates to the calendar data.
The value of this property SHOULD be used by calendar user agents to limit the polling interval for calendar data updates to the minimum interval specified.
there is nothing in the standard specifying the update rate.
However Microsoft has a custom way to control the update frequency: with a custom calendar property: X-PUBLISHED-TTL (see microsoft msdn calendar) This specification modifies the definition of the "URL" property to allow it to be defined on an i Calendar object.