I wrote this table because I like to recycle
calendars. They often have photographs I don't want
to throw away! But how do you find out which year
matches which?
To use this chart, find the year for which you want a calendar.
Then read up or down the table in the same column to find another
year for which you have a calendar. That calendar has the same
pattern of months and days of the week as the desired
calendar.
If the year is marked with an "A" and a "B", then the year is a
leap year. Either find another year with the same letters in the
same columns as the desired year, or a nonleap year. In the
latter case, the months of January and February (save for February
29) will be the same as the "A" marking, and the next column
(matching the "B" marking) will have the same months
MarchDecember.
For example, suppose you are looking for a calendar
for 2013. Look up the column containing 2013. The
first entry above is 2008A, a leap year, so no
good. Continue on to 2002, 1991, 1985, 1974  any
calendar for these years will also be good for 2013.
The other years are leap years, and only partly work
(e.g., 1996 will be OK for MarchDecember, but not
JanuaryFebruary.
If I wanted a calendar for 2012, then 1984 would be a
matching leap year with the same month to day of the week
pattern.
The heading reflects the starting day of the week for
January 1. (If a leap year, use column "A")
The second half of the table then shows what day of the
week on which each month starts.
Read down the column you have found for the desired
year to the month in the desired year for which you
want the starting weekday.
Then read back to the left hand column for that row,
and you will find the appropriate day of the week.
Remember that if the year is a leap year, you should
read down column 'A' for Jan and Feb, and column 'B'
for all other months.
Example: You want to know what day of the week May
starts on in 1984. Since 1984 is a leap year, and May
is after February, find the column containing 1984B,
and read down the column until you find May. Then
read across to the left hand column to find that it
starts on a Tuesday.
Finally, to get the day of the week for any given
date, subtract 1 from the day of the month, divide by
7, and take the remainder. Then add the number in the
left hand column for the row of the month you found
above. The answer is then the day of the week,
according to the numbers in the left hand column.
Example: On what day of the week does 19 May 2017
fall? 2017 is in the last column of the table, and 1
Jan is a Sunday. Look down the column to find May,
which starts on a Monday, and has number 0. Subtract
1 from the date giving 18, divide by 7 gives 2 and 4
remainder. Add the 0 from the previous step, giving
4, which is a Friday. Answer: 19 May 2017 is a
Friday.
PS: You can also find out upon what dates a given day
of the week falls in a similar way. Find the first
day of the given month as above, then starting at 1
for that day, count down the table (and back to the
top if necessary) to find the required day of the
week. The count will give you the first day of the
month for the required day of the week, and then add
multiples of 7 to find the remaining dates.
Example: When are the Mondays for February 2018?
First find that the 1st of February 2018 falls on a
Thursday as above. Then count down and around to find
that Monday is the 5th. (Thursday 1, Friday 2,
Saturday 3, Sunday 4, Monday 5). So the Mondays in
February 2018 are the 5th, 12th, 19th and 26th.
