aman704, thank you for your patience. I am working on a solution that will work in current versions of the plugin, but keep in mind we are releasing a large overhaul on the query building for the plugin and this will be much simpler to accomplish going forward with easy ways to hook into the query building for any event queries and set limits like you are requesting.
Just to clarify you are wanting the RSS to show the previous 24 hours? And are you looking for “previous” day or 25 hour range (aka if it 3PM currently get all events since 3PM yesterday vs just getting all events that happened yesterday)?