Introduction

In modern times, most of the countries in the world use “Gregorian calendar” in their daily life, and every event, holiday are based on this calendar system [1], [2]. It is introduced in October 1582 by Pope Gregory XIII. In the Gregorian Calendar, a year is composed of 12 months. Each month has a different number of days. For example, January has 31 days, February has 28 days, and sometimes 29, April has 30 days, and so on. Sometimes, the dates become confusing especially when a particular day like Monday, is the first day in a month, and the second or even the seventh in another month, sometimes holidays which are on a specific date such as 24 December, could be located during the weekdays (e.g., in 2019), while it can be in weekends in another year (e.g., 2022). It appears that the existing calendar system becomes a little bit confusing for most of us, and some of us need something much more uncomplicated to rely on.

What happens if we create a more organized Calendar in which the days and dates in a month do not change? For example, Monday will always be the first day of any month. The holidays will have the same date and day in a year. For example, 24 December will always be on Wednesday every year and so on. Do we think that this method might be easier to memorize and to use? Moreover, humans always develop and invent new things every day to facilitate their lives. So why not develop an easier way to count days, weeks, and months in a year?

In this article, the author proposes a calendar year of 13 months instead of 12, in which each month contains exactly 28 days, the additional day which is the number 365 in a year is called yearday, and it is not considered in any month, because it is the end of the year and not a month. The advantages and disadvantages of the proposed Calendar are stated in this paper.

Methods and development

 A year on earth has approximately 365.2425 days and 12 months. Each month has almost between 28 and 31 days, according to the Gregorian Calendar. In the current Gregorian Calendar, a year has nearly 52.1428 weeks. A week always starts on a specific day (such as Monday). However, the date of the day is different from a year to another. For example, the first day in January 2020, is Wednesday, while it is Friday in 2021. Moreover, the first day of each month also changes. For instance, the first day in January 2020 is Wednesday, while it is Saturday in February 2020, and Sunday in March 2020. Christmas in 2020 is on Thursday 20, while it is on Friday 24 in 2021.

It becomes more complicated when a leap year is added every four years, and an additional day is added to the month of February, which becomes equal to 29 days instead of 28 every four years. In this article, we suggest a new calendar system weekly-based in which it has 13 months to minimize the complexity. In order to create such Calendar, we should follow the mentioned steps as below:

• We start to define a week. A week has only 7 days, and it always starts on Monday.
• A month has only 4 weeks, in which the total number of days becomes equal to 28 only (7 days x 4 weeks)
• All months have precisely the same number of days, and they start exactly with the same day (Monday) and end with the same day (Sunday)
• The number of days in a month cannot change even during a leap year. They are always fixed to 28 days per month, whatever is the year.
• The number of weeks in a year is fixed to 52. In fact, the number of weeks should be 52.1428 (365 days / 7 days = 52.1428); however, we approximate it to 52 for simplicity
• After doing all these calculations, the total number of days in a year becomes equal to 364 days per year (52 weeks per year x 7 days per week).
• The remaining days of the year are named “Yeardays,” in which they are not included in any month, but at the end of a year. They are just added at the end of the year, in which they separate a year from the next one. For example, the day number 365 is called “Yearday 1” which is the end of a year and it is not included in any month or week, For the case of a leap year, the day number 366 is called “Yearday 2”, in this way the Calendar doesn’t change. An example is shown in the following tables:

• Because each month has 4 weeks, the total number of months becomes equal to 13 (364 days per year / 28 days per month = 13).

Results and discussions

 If we elaborate on all the above steps, we can create a new calendar year, which has the following form:

Figure 1: Proposed Calendar with 13 months in a year and 28 days in a month.

The number of days in a sequence in a calendar year will also have the following form:

Figure 2: Sequence numbering of days in the proposed Calendar.

 The following Figures compare the Gregorian Calendar to the proposed one in this article.

Figure 3: Comparison between the proposed Calendar and the Gregorian Calendar for the year 2020.

Figure 4: Comparison between the sequence numbering of the days in a year for the proposed Calendar and the Gregorian Calendar for the year 2020.

From the above Figures, it is clear that the proposed Calendar in this paper has a more systematic organization of the days in a week, month, and year. The first day of a month always starts on Monday, and the last day of each month is always Sunday. Therefore, counting days becomes an easy task, and there is no need for complex algorithms to predict the days and dates in previous years.

The calculation of the date for a specific day is straightforward and can be done using the following proposed equations:

 and 

 Where w is the week number in a month (w in [1,4]) or a year (w in [1,52]).

 Example:

Calculate the date of the Monday in the third week of a month and check it on the Calendar to see if it is correct.

Answer:

Monday=1+7(w-1)=1+7(3-1)=15 

Example:

Calculate the day number of Wednesday located on the 36^th week of the year, and check it on the Calendar to see if it is correct.

Answer:

 Wednesday=3+7(w-1)=3+7(36-1)=248

To conclude the study, a comparative table between the proposed Calendar and the Gregorian Calendar shows the advantages and disadvantages of each system.

Conclusion

 In this article, the author proposes an original calendar based on 13 months instead of 12. Each month has exactly 28 days. The new Calendar is much easier to understand and calculate. We do not need complex algorithms to calculate the dates and days in a year. Moreover, the proposed Calendar fixes the days and their dates in a month and year. Therefore, the dates will be the same whatever is the year, contrary to the Gregorian Calendar. Are we able to apply this new Calendar in our daily life? Does it seem logical to try it and see what it can change in our life? The author asks the readers to give their comments in order and suggestions.

References

 [1]   C. A. Ronan, "The Gregorian Calendar," The New Encyclopaedia Britannica, pp. 602-603.

[2]    E. L. Cohen, "Adoption and reform of the Gregorian calendar," Math Horizons, vol. 7, no. 3, pp. 5-11, 2000.

[3]    N. Dershowitz and E. M. Reingold, "Calendrical calculations," Software: Practice and Experience, vol. 20, no. 9, pp. 899-928, 1990.