Day of the week of Christmas and New Year

Day of the week of Christmas and New Year is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Task

Determine programatically and show on this page on what weekday Christmas Day, 2021 and New Year's Day, 2022 will fall or did fall.

AWK

<lang AWK>

1. syntax: GAWK -f WHAT_WEEKDAYS_WILL_CHRISTMAS_AND_NEW_YEAR.AWK

BEGIN {

   fmt = "%Y-%m-%d is a %A"
   print(strftime(fmt,mktime("2021 12 25 0 0 0")))
   print(strftime(fmt,mktime("2022 01 01 0 0 0")))
   print("")
   fmt = "%d %b %Y is %A"
   print(strftime(fmt,mktime("2021 12 25 0 0 0")))
   print(strftime(fmt,mktime("2022 01 01 0 0 0")))
   exit(0)

} </lang>

Output:

2021-12-25 is a Saturday
2022-01-01 is a Saturday

25 Dec 2021 is Saturday
01 Jan 2022 is Saturday

Factor

Works with: Factor version 0.99 2021-06-02

<lang factor>USING: calendar calendar.english calendar.holidays.us formatting kernel sequences ;

CONSTANT: msg

   "In %d, New Years is on a %s, and Christmas is on a %s.\n"

day-name ( ts -- str ) day-of-week day-names nth ;

christmas ( n -- str ) christmas-day day-name ;

new-years ( n -- str ) new-years-day day-name ;

holidays ( n -- ny ch ) [ new-years ] [ christmas ] bi ;

.holidays ( seq -- ) [ dup holidays msg printf ] each ;

{ 1578 1590 1642 1957 2020 2021 2022 2242 2245 2393 } .holidays</lang>

Output:

In 1578, New Years is on a Sunday, and Christmas is on a Monday.
In 1590, New Years is on a Monday, and Christmas is on a Tuesday.
In 1642, New Years is on a Wednesday, and Christmas is on a Thursday.
In 1957, New Years is on a Tuesday, and Christmas is on a Wednesday.
In 2020, New Years is on a Wednesday, and Christmas is on a Friday.
In 2021, New Years is on a Friday, and Christmas is on a Saturday.
In 2022, New Years is on a Saturday, and Christmas is on a Sunday.
In 2242, New Years is on a Saturday, and Christmas is on a Sunday.
In 2245, New Years is on a Wednesday, and Christmas is on a Thursday.
In 2393, New Years is on a Friday, and Christmas is on a Saturday.

Julia

See also https://docs.julialang.org/en/v1/stdlib/Dates/#Dates.format-Tuple{TimeType,%20AbstractString} <lang julia>using Dates

println("Christmas 2021: ", Dates.format(DateTime(2021, 12, 25), "E, U d, Y")) # "Christmas 2021: Saturday, December 25, 2021" println("New Years Day 2022: ", Dates.format(DateTime(2022, 1, 1), "E, U d, Y")) # "New Years Day 2022: Saturday, January 1, 2022" </lang>

Perl

<lang perl>#!/usr/bin/perl

use strict; # https://rosettacode.org/wiki/What_weekdays_will_Christmas_and_New_Year use warnings; use Time::Local;

for (

 ['Christmas 2021', 25, 11, 2021 ],
 ['New Years 2022', 1, 0, 2022 ],
 )
 {
 print "$_->[0] ", qw( Sunday Monday Tuesday Wednesday Thursday Fridat Saturday )
   [(localtime timelocal(0, 0, 12, @{$_}[1..3]))[6]], "\n";
 }</lang>

Output:

Christmas 2021 Saturday
New Years 2022 Saturday

Phix

with javascript_semantics
include timedate.e
procedure nyc(integer year)
    string ny = format_timedate({year,1,1,0,0,0},"Dddd"),
           cd = format_timedate({year,12,25,0,0,0},"Dddd")
    printf(1,"In %d, New year's day is on a %s, and Christmas day on a %s.\n",{year,ny,cd})
end procedure
papply({1578, 1590, 1642, 1957, 2020, 2021, 2022, 2242, 2245, 2393},nyc)

Note the builtin timedate type does not officially support dates prior to 1752... the fact that the first three lines agree with other entries on this page is pure luck.

Output:

In 1578, New year's day is on a Sunday, and Christmas day on a Monday.
In 1590, New year's day is on a Monday, and Christmas day on a Tuesday.
In 1642, New year's day is on a Wednesday, and Christmas day on a Thursday.
In 1957, New year's day is on a Tuesday, and Christmas day on a Wednesday.
In 2020, New year's day is on a Wednesday, and Christmas day on a Friday.
In 2021, New year's day is on a Friday, and Christmas day on a Saturday.
In 2022, New year's day is on a Saturday, and Christmas day on a Sunday.
In 2242, New year's day is on a Saturday, and Christmas day on a Sunday.
In 2245, New year's day is on a Wednesday, and Christmas day on a Thursday.
In 2393, New year's day is on a Friday, and Christmas day on a Saturday.

Python

<lang python> iimport datetime

weekDays = ("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday") thisXMas = datetime.date(2021,12,25) thisXMasDay = thisXMas.weekday() thisXMasDayAsString = weekDays[thisXMasDay] print("This year's Christmas is on a {}".format(thisXMasDayAsString))

nextNewYear = datetime.date(2022,1,1) nextNewYearDay = nextNewYear.weekday() nextNewYearDayAsString = weekDays[nextNewYearDay] print("Next new year is on a {}".format(nextNewYearDayAsString)) </lang>

Output:

This year's Christmas is on a Saturday
Next new year is on a Saturday

Raku

<lang perl6>my @d-o-w = < Sunday Monday Tuesday Wednesday Thursday Friday Saturday >;

.say for (flat 2020..2022, (1500 .. 2500).roll(7)).sort.map: {

    "In {$_}, New Years is on a { @d-o-w[Date.new($_,  1,  1).day-of-week % 7] }, " ~
    "and Christmas on a { @d-o-w[Date.new($_, 12, 25).day-of-week % 7] }."

}</lang>

Sample output:

In 1578, New Years is on a Sunday, and Christmas on a Monday.
In 1590, New Years is on a Monday, and Christmas on a Tuesday.
In 1642, New Years is on a Wednesday, and Christmas on a Thursday.
In 1957, New Years is on a Tuesday, and Christmas on a Wednesday.
In 2020, New Years is on a Wednesday, and Christmas on a Friday.
In 2021, New Years is on a Friday, and Christmas on a Saturday.
In 2022, New Years is on a Saturday, and Christmas on a Sunday.
In 2242, New Years is on a Saturday, and Christmas on a Sunday.
In 2245, New Years is on a Wednesday, and Christmas on a Thursday.
In 2393, New Years is on a Friday, and Christmas on a Saturday.

Wren

Library: Wren-date

This uses the same years as the Raku example.

The actual days for 1578 may have been different as the Gregorian calendar didn't start until 1582. <lang ecmascript>import "./date" for Date

var years = [1578, 1590, 1642, 1957, 2020, 2021, 2022, 2242, 2245, 2393] for (year in years) {

   var newYear = Date.new(year, 1, 1).weekDay
   var xmas = Date.new(year, 12, 25).weekDay
   System.print("In %(year), New year's day is on a %(newYear), and Christmas day on %(xmas).") 

}</lang>

Output:

In 1578, New year's day is on a Sunday, and Christmas day on Monday.
In 1590, New year's day is on a Monday, and Christmas day on Tuesday.
In 1642, New year's day is on a Wednesday, and Christmas day on Thursday.
In 1957, New year's day is on a Tuesday, and Christmas day on Wednesday.
In 2020, New year's day is on a Wednesday, and Christmas day on Friday.
In 2021, New year's day is on a Friday, and Christmas day on Saturday.
In 2022, New year's day is on a Saturday, and Christmas day on Sunday.
In 2242, New year's day is on a Saturday, and Christmas day on Sunday.
In 2245, New year's day is on a Wednesday, and Christmas day on Thursday.
In 2393, New year's day is on a Friday, and Christmas day on Saturday.

XPL0

<lang XPL0>func WeekDay(Year, Month, Day); \Return address of day of week int Year, Month, Day; \Works for years 1583 onward int DayOfWeek, Names; [if Month<=2 then [Month:= Month+12; Year:= Year-1]; DayOfWeek:= rem((Day-1 + (Month+1)*26/10 + Year + Year/4 + Year/100*6 + Year/400)/7); Names:= ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]; return Names(DayOfWeek); ]; \WeekDay

[Text(0, "This Christmas is on a "); Text(0, WeekDay(2021, 12, 25)); CrLf(0); Text(0, "This New Year's Day is on a "); Text(0, WeekDay(2022, 1, 1)); CrLf(0); ]</lang>

Output:

This Christmas is on a Saturday
This New Year's Day is on a Saturday