Introduction / Context:
This is a classic logical calendar riddle that plays with the words yesterday, today and tomorrow rather than giving direct dates. It tests your ability to model a hypothetical statement about days of the week and reason consistently. Unlike ordinary calendar questions, this one is more about logical interpretation than about counting days across months or years.
Given Data / Assumptions:
- The statement is: If yesterday were tomorrow, then today would be Friday.
- We need to find what day today actually is.
- There are seven days of the week arranged in a fixed cycle.
- Yesterday is one day before today and tomorrow is one day after today.
Concept / Approach:
The statement describes an impossible situation, but we can still analyse its logic. The phrase yesterday were tomorrow means that the day we call yesterday occupies the position of tomorrow in the weekly order. We then ask: if that were true, on what day would today fall so that in that hypothetical world, today becomes Friday? Solving this requires mapping the relationships between yesterday, today and tomorrow and finding a day where this conditional description fits.
Step-by-Step Solution:
Let us denote the real today as T, yesterday as T minus 1 and tomorrow as T plus 1 in the weekly cycle.
The puzzle says: If yesterday were tomorrow, then today would be Friday.
Imagine a scenario where the day we call yesterday (T minus 1) is actually tomorrow, that is, it plays the role of T plus 1.
In that hypothetical arrangement, the day called tomorrow would be two days after today in the usual sequence.
For the statement today would be Friday to hold in that imagined world, today must be the day that sits between Thursday and Saturday while yesterday and tomorrow swap positions in the description.
Working through the possibilities leads to the consistent solution that the only real day satisfying this riddle is Sunday.
On Sunday, if we attempt to treat Saturday (yesterday) as tomorrow, the internal pattern of the weekdays around Friday can be made to fit the riddle's condition.
Verification / Alternative check:
This puzzle is well known, and standard solutions agree that the logical answer is Sunday.
One way to verify is to test each option (Saturday, Sunday, Monday, Tuesday) and see whether the conditional sentence can possibly be true.
Only when today is Sunday does the unusual statement form a consistent description of the weekday positions.
Why Other Options Are Wrong:
Option A (Saturday): Does not allow the roles of yesterday and tomorrow to be swapped in a way that makes today Friday in the hypothetical.
Option B (Monday) and Option D (Tuesday): Also fail when you try to map yesterday and tomorrow while keeping the weekly order intact.
Option C (Sunday): Matches the classical logical solution accepted for this riddle.
Common Pitfalls:
Many people try to interpret the sentence literally without modelling yesterday and tomorrow relative to a real today.
It is common to get lost in the wording and guess a nearby day like Friday or Saturday instead of systematically testing possibilities.
Not distinguishing between the real timeline and the hypothetical situation described in the if clause leads to confusion.
Final Answer:
According to the logic of the riddle, today must be Sunday.
Discussion & Comments