简约日历 - 简单好用无广告 is a minimalist and clean calendar app with no ads. It includes features like legal holidays, traditional Chinese festivals, customizable reminders, and various Chinese traditional color themes. The app offers a smooth user experience, with no lag during navigation. It also provides dark mode, font customization, and a date calculator for easy date calculations.

The app ensures a comprehensive display of both Gregorian and lunar calendar holidays, as well as special days like solar terms and Nine Days' Fever. Users can set up personalized reminders, schedules, and even birthdays, including lunar birthdays. The data syncs automatically via iCloud, ensuring data retention even when switching devices or reinstalling the app.