Each feed lists events for the coming 30 days in a given region
Some interesting features using parameters:
tag: limit events to a specific tag. This will for example give you a feed of all your organisation's events, if you do remember to tag all your events with a specific tag.
daylimit: limit future events to some number of days.
near[distance]: limit to events near a specific location and distance (default to 20 km).
Those parameters can be used with feeds, and also on the map of the main calendar