Annual Holiday Calendars is a free and easy-to-use application designed for iPhone users. This simple perpetual annual calendar app displays the current year and the following year, allowing users to easily navigate between them using the left and right buttons.

One of the key features of this app is the ability to switch the first day of the week between Sunday or Monday, catering to different users' preferences. Additionally, the app highlights today's date, making it easy for users to quickly identify the current day.

Annual Holiday Calendars also provides useful information such as the monthly week number and the percentage of days that have elapsed in the current year. This can be helpful for tracking progress or planning activities.

Furthermore, users have the option to set their own holidays, whether it's a national holiday, personal event, or even the full moon. The app allows users to input holidays using the year/month/day (YYYYMMDD) or month/day (MMDD) format, providing flexibility for different types of events.

Overall, Annual Holiday Calendars is a straightforward and practical app for those who want a simple way to keep track of dates, holidays, and important events. Its user-friendly interface and customizable features make it a useful tool for both personal and professional use.