(This is one of two articles about calendar dates. The other article is the Ancient Greece article where I want to represent each day of a 366 day year as an image of a person.)
There are mnemonic ways of telling someone the day of the week based on some maths. I can write more about it in the future but here are some graphics to get you thinking..
If each year has one of 7 digits and each month has 1 of 12 digits [obtained from a look up table] then you can add it up and add the day of the month such as 30th; and then divide it all by 7. The remainder indicates which day of the week the date is.
Note: When I made 100 cartoon people, I wanted their colours to match this system.
Maybe the list of 12 images for 12 months is of limited use. Why would I imagine a story involving a day image or action (1 to 31) and a month image if there is a system of images each representing a day and month together?: within the 31 x 12 images.
Also, if I want to remember major events of this year's January, I could have problems if I imagine a story involving the January tambourine image:
Next year, I would be using a tambourine image also for storing major events from next year's January. (but the two January's could become muddled in my memory.) It is doable but it would be good to have 12 unique month images for this year and/or 12 other unique images for next year.
There might be a very structured approach to doing that; or maybe one would just note a news story image in January and rote learn that the image represents January of that year.
Another idea is to colour the 12 month images according to the colour of the table above: to help me to remember the adjustment that is needed in the calendar maths. (See the Colours article.)
An example is 3rd April 2021: I want the 3 of the date, the offset of April and the single digit I have for 2021: 3, 5, 6. I add them. That is 14. I find the remainder of divising that by 7: remainder 0. In the little table above, 0 matches a Saturday. So the answer is Saturday. Note that a leap year needs a 1 added to the maths before the division by 7 step happens: if the date is at the 29th February or later in the year: days prior to that need no such adjustment.
The 100 people of the People from 00 to 99 article have hair colours chosen to try to match the 100 year digits. So, for 2079, person 79's hair colour is relevant to the calendar date maths (subject to human error colour filling by me!).
Another approach to knowing the day of a date that occurs this year is to think of Monday to Sunday as numbers 1 to 7 (for example); then represent January's first day of the month, February's first day of the month and March's first day of the month (the 1st day of each month) as a 3 digit number: in 2022, Saturday=6 in January, Tuesday=2 in February, and Tuesday=2 in March; so a 3 digit number is 622. 622 is matched, in this course, with a cartoon person image who has a name. So all 12 months of the year is 4 lots of 3 digit numbers: if you can learn the 4 relevant people in sequence then that is a quick way to get to the day that starts any month of this year. If you need to know the day of 10th February then you can deduce it from knowing that 1st February is a Tuesday.