You can show the real date on the Google Calendar icon instead of the permanent “31” on your Android phone, though not officially. Currently, there is no setting in the calendar app to get this handy feature, but custom launchers like Nova Launcher will bring it on all Android phones. To show the current date on your Calendar app icon, install the Nova Launcher from Play Store (link) and set it as your default launcher. To make it default home app, go to Settings > Apps & Notifications > Default apps > Home app > select Nova Launcher. Note that this setting is for Android 10 phones run on stock Android. The Google Calendar app gives you all the tools you need to get organized and informed. It provides multiple views of your day, week and month, you can create and view to-dos alongside your events, add goals and the Calendar will schedule time for them automatically, and more. Google Calendar also provides several advanced features for everyone’s needs. You can manage appointments across multiple time zones, get alerts for all events by default, quickly search down to specific calendars, dates, locations, or participants, and it works with all calendars on your phone, and more.
