Questions tagged [calendar-computations]
This tag is for questions about combinatorial and computational issues with regards to calendar systems. A typical, well-known mathematical result in this direction is John Conway's Doomsday Algorithm for computing the "day of the week" associated to a given date.
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Probability of Christmas falling on a particular day of the week
What is the probability that Christmas (on a randomly chosen year) falls on a Monday, Tuesday, Wednesday, &c.? Accounting for the leap years and the 400-year repeating cycle, I wrote a program to ...
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Calculating Recurring Work Schedule Off Days in a Given Month [closed]
I have a work schedule that uses a cycle like this:
Day 1: Morning shift
Day 2: Night shift
Day 3: Day off
Day 4: Morning shift
Day 5: Night shift
Days 6-8: 3 days off
Assuming today, May 4th is the ...
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How often would the season cycle be "reset" if the year was 360 days?
I am learning about ancient calendars relating to the sun, and many used a 360 day calendar. If you did that, without adding "5 extra non-days per year" (or 6 on a leap year), then assuming ...
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What is the probability of someone being born both on a Good Friday that is also Friday the 13th
I was born on April the 13th 1990. The day was also Good Friday. I'm wanting to know what the probability/chances of being born on a Good Friday that is also a Black Friday is/are to have an ...
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Decoding Gauss' Easter Algorithm
In 1800, Gauss published this algorithm for computing the date of Easter in a given year $year$:
$a = year \mod 19$
$b = year \mod 4$
$c = year \mod 7$
$k = \lfloor year/100 \rfloor$
$p =...
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Solve for numbers to appear on two six-sided dice
I have a small wooden calendar that uses two six-sided dice to display day of month. One die carries numbers 0, 1, 2, 6, 7, 8 and the other carries 0, 1, 2, 3, 4, 5. The six of course doubles as the ...
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What is the probability that the fourth business day of the month is Thursday? [duplicate]
This is question 3.16 from the book "Quant Job Interview Questions and Answers" by Mark Joshi et al. The solution given in the book states that for the fourth business day of the month to be ...
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Calculating Calendar Adjustment
I have a data with the Date and Volume column like below, where I am trying to adjust the calendar, the dates are week-ending dates, hence some of the data is missed since May ended with a full week ...
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Dates on which a day falls, in given month and year.
I was recently given the following problem on a test:
Find the dates on which Sunday fell in July, $1776$.
First, I noted the date on the day of test — $15$ October $2023$ to be a Sunday. Thereafter,...
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Formula to find the date given a specific year, month, and day of the week
I need a formula to get me to the first or third specified day of the week of the following year.
So, here is the information I am presented. I have a year (y), a month (m) and a day of the week (n). ...
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Book that goes over mathematics of calendar computations?
What is a good book that goes over mathematics of calendar computations (e.g., calendar systems, date of Easter, etc.)?
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What adjustments would be necessary to have a remainder of 0 associated with Sunday?
I was reading this below and I had a question:
Link
Take a look under "The Key Value Method" where it says "A remainder of 0 corresponds to Saturday, 1 means sunday, etc."
My ...
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Why do you subtract 1 in a leap year if the date falls before March?
I was reading this below and I had a question:
Link
Take a look under "The Key Value Method" where it says "If your date is in January or February of a leap year, subtract 1."
I ...
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Months and notes. Pure coincidence?
There are $12$ months in a year and $12$ notes in the chromatic scale. Moreover, there are $7$ long and $5$ short months and there are $7$ white and $5$ black keys in each octave on the piano ...
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Day of week - 4th June, 2002 using Zeller's Rule
I know how to calculate day of week using Zeller's Rule, but the answer is coming as Sunday, while the correct answer is Tuesday. Where am I doing wrong? Please explain your answer step-by-step. ...
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