4 Answers
4

You start with "Consider the following equation: 5/15 plus some other number is 5/16." And if we use US or Asian date format then it is May 15th plus some other number is May 16th. And that some other number is One day.

Ok, ok. I know that it is wrong, because

If you subtract March 6th from May 12th you don't get January 12th of last year, and the step is only 2 days, so we cannot interpret 1/12 as "a month". But we do get International Women's Day. And if we add Computing day (256th day of the year) and a day 2 days after International Women's Day, we get a Transgender Day of Remembrance. Is it «lovely»?

$\begingroup$I like this answer. But I think I might've confused too many people with the "equation that claims to be equal 1 but isn't actually equal 1". The hint that downplays the significance of this last line is not a farce.$\endgroup$
– Samy BencherifApr 10 at 0:03

I will begin to start answering my own question. It is not too late to win the bounty. Once it expires I will fully explain my puzzle.

Hint 1 Explained:

The last sentence is most significant when posted anywhere but a puzzle-enthusiast webpage.

Here I am indicating that the last sentence would inform you that
there is a puzzle in the first place--which is unneeded on a puzzle
website. 9/12 + 3/10 is equal to 1.05 which is 5% off of what I said
it was (one). The off-ness is a clue that this text is not only a
wonky passage about fractions. The 5% represents the little extra there is than meets the eye. All of that aside, the point of this hint is to say that the last sentence is a bit of a red herring if you already know there is a puzzle involved.

Hint 2 Explained:

I left out tags, namely cryptography and cyphers. This is
indicated by the use of the word "cryptic" and moreso by the
hyperlinked period that leads to a webpage about cyphers.

Upon visiting that website you should consider that my message
contains some kind of cypher. Considering my message is lines of
readable text with numbers (not garbled text), many of the cyphers can
be eliminated. What remains is A1Z26, ASCII, Anagram, Acrostic, Book,
Substitution. It is possible that only the numbers are involved in the
cypher, or perhaps both the numbers and the text together. Maybe
decoding Acrostically results in some Caesarically encoded message 😈.

Hint 3 Explained:

Hint 3 truly is more confusing than it is helpful, but being the kind
of person that I am, and delighted by an intriguing coincidence, I
felt obligated to keep it in there. If you click "share" under the
question you will be given a URL:
https://puzzling.stackexchange.com/q/81535/58232.

There is a catch, but if you decrypt this url using the same cypher I
used in the above message you will get the message "solved". The catch
is that you must be willing to backtrack, that is, you go back to
the start when you reached the end. Under this logic, if I asked you
for the fifth letter of "abc" you should say "a-b-c-a-b, ah yes the
5th letter is b!"

How to solve the puzzle

Figure out what kind of cypher I used and use it to decode the passage. The first answer containing the secret message will receive the bounty.

Please feel free to ask questions if you need help completing the puzzle. If it is possible to extend bounties, I may do this.

Bonus Hint Explained:

I initially forgot about this one. In the comments for one of the
answers I was talking about the significance of the last sentence and
I included a little hyperlink to
https://en.wikipedia.org/wiki/The_Wide_Window. This is a reference to
how one of the characters of that book uses grammatical errors to hide
a secret message, because only those who truly know her would
recognize bad grammar as completely out of character for her.

This book was a large influence that got me interested in cyphers in the first place.

Anyway it was a good book; cypher or no cypher.

Edit:
Cough Cough. Book. Cypher. Book Cypher. It's a book cypher.
And it is not of the book I linked to, or any actual book in fact, As I can't guarantee everyone has access to the same editions of books. I will be posting the answer soon! :)