The Google Calendar app hasn't really changed much over the years. As a pre-installed staple on most Android devices, the interface is definitely lacking in some areas. Google knows this, and has plans in the pipeline to completely revamp Calendar's UI alongside Android 5.0's official release.
But, if you'd rather not wait for the Lollipop update to come your way, a new Xposed module will allow you to tweak Calendar's interface right now. With options for nearly every aspect of the Month overview interface, you'll be able to see more of your upcoming schedule at a glance.
First up, head to the Download section of your Xposed Installer app and search GCalMonthDetails, then tap the top result.
From here, swipe over to the Versions tab, then hit the Download button next to the most recent entry.
After a few seconds, Android's installer interface should come right up. Tap Install on this screen.
When that's finished, you'll get a notification from Xposed letting you know that the module needs to be activated before you can use it. Tap the Activate and reboot button on this notification, and Xposed will take care of the rest.
When you get back up, open GCalMonthDetail from your app drawer. The interface is simple—a set of sliders allow you to adjust the various elements of Google Calendar's Month view.
Changes will take effect after you've closed and re-opened your Google Calendar app, so play around with the various sliders in GCalMonthDetail until you find the look that's right for you.
With the sliders adjusted to your liking, you'll now be able to see lots of extra detail in the month overview of your Google Calendar app. Where before, appointments were only denoted by a tiny colored rectangle, event descriptions and times are now clearly seen. Simple, yet effective, right?