13 Month Fixed Calendar is a productivity app developed by erkantr.
Download Statistics
13 Month Fixed Calendar has been downloaded 24 thousand times. In the last 30 days, the app was downloaded 1.1 thousand times.
User Ratings
13 Month Fixed Calendar is rated 2.76 out of 5 stars. The rating is based on 170 ratings.
App Information
13 Month Fixed Calendar is FREE to download. The APK download size is 4.62 MB. The latest version available is 2.2.3. The last update was on May 13, 2025.
Technical Requirements
The app has a content rating of Everyone. The app has been available on Google Play March 2024.
Description
The International Fixed Calendar is a calendar system where every year aligns with the same days of the week and dates, ensuring consistency in weekly patterns. It was first proposed by Moses B. Cotsworth in 1902. This calendar divides the year into 13 equal-sized months, each consisting of 28 days, resulting in a total of 364 days. Leap years are calculated similarly to the Gregorian calendar, with an additional day added every four years. However, in the International Fixed Calendar, the extra day is inserted between June 28 and July 1, known as "Sol," effectively creating a 365-day leap year.
While the month names align with those of the Gregorian calendar, an extra month called "Sol" is inserted between June and July. This arrangement starts each year on a Sunday and ends on a Saturday, ensuring that the first day of each month falls on a Sunday and the last day on a Saturday. This consistency aids in planning and daily routines.
The International Fixed Calendar enhances calendar consistency by ensuring that the same dates align with the same weekdays each year.
Recent changes:
## Version 2.2.3
This version includes significant improvements aimed at enhancing the app’s core functionality and user experience.
- User interface updated. - Fixed issues related to Day of the Year and Leap Day. - Settings screen added. - Added Dark Mode and custom theme color options. - Added info screen explaining the 13-month calendar and its history. - Added support for German, French, Spanish, Portuguese, Polish, Italian, Russian, Chinese, and Arabic languages.
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I like the 13th month concept. You are ahead a few days. Writing this review, and currently the app says it's on day 21 of April. When it would actually be on the day sixteen. Yes I did the comparison with the Gregorian calendar and traced back from February 2026 the following year to come, the month is a perfect alignment with the days matching perfectly. Aside from other comments editing dates and setting reminders would be an excellent edition. Keep it up! Looking forward to new improvements
★★☆☆☆Ladislav Piaček· Oct 25, 2025
Please, if you can add possibility to set starting day of calendar from official calendar, so I can really use it then. I want to match weekdays each eyar. e.g. 30th december 2024 gregorian = 1. January 2025 in fixed.
★☆☆☆☆jason poggenpoel· Jul 13, 2026
it's the normal calendar and not the true 13-month calendar... False information.
★☆☆☆☆SageStormCloudMoonGoddess· Apr 3, 2025
I'd give it zero stars, but that's not an option. This app Does Literally Nothing except Show you an image of the Calendar. It needs to be taken down.
★☆☆☆☆Pro Banda· Apr 10, 2025
Awesome. But in setting there needs to be option to change the starting day to New year solar eclipse and New moon variation for starting of a month. 🙏
★★☆☆☆RICLEY75· Mar 3, 2025
Page looks good but 7,14,21,28 are missing in every row on every month until I turn my phone to view in horizontal view then the number come back, but also it's not on the right date and the day not highlighted on which actual day it is and more than one month has the same day highlighted, what's what, please fix I really like this concept, and your is the only of its type. It would be great to have a settings menu to change basics like to fit on phone screen
Google Play Rankings for 13 Month Fixed Calendar
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