"Scheduled Deployments" have almost no benefits, but lots of downsides. Notably, there's no distinction between bug fixes and feature releases, it will cause undue periods of stress and wasted workhours, bugs will be plentiful, and it will generally just be a mess.
However, once you start talking about "scheduled version releases", now you have something to work with. A version is a collection of features all released at once. By using the version ideology, you can actually improve the number of bugs that are caught before deployment to production, make it easier to identify which version introduced a given bug, and provide product stability for users in-between releases.
In this case, you'd have a regularly scheduled release every few weeks or months that contain many new features, which have all ideally been through QA and UAT (User Acceptance Testing). These extra steps that you apparently lack in your current lifecycle are important, and you shouldn't be skipping them.
Also, by going with a "version" route, you can test that you're not introducing bugs that can only be found by end-to-end testing. You could still use hotfixes if you need to, but hopefully with better QA/UAT, they would be rare.
So, in summary, as part of a comprehensive software development lifecycle strategy, scheduled feature releases drastically reduce the number of bugs and improves the quality of the product.