Who Watches the Watchmen? (May 2026 Challenge Question)

That's a great question! Taking it to the absurd extreme of both errors being per second, one watch would stop, while the other would run 1.5 times too fast. The next uncertainty is the range of the watches: 12-hour, 24-hour, weekly, monthly, lunar cycle, tides, or even the rare watch that tracks the numeric year.

Clarification of #9:

Times "My watch" is correct: 0,1800,3600,5400,... hours

Times "Your watch" is correct: 0,1200,2400,3600, ... hours

Both correct: 0,3600,7200,... hours

Clarification of #9:

Oops, should be days...

Times "My watch" is correct: 0,1800,3600,5400,... days

Times "Your watch" is correct: 0,1200,2400,3600, ... days

Both correct: 0,3600,7200,... days

This is a Deceptively Simple Situation.

IF THE CLOCK SPEED IS THE SAME (correct speed) on both watches:

1: each watch will show the same time again in exactly12 hours.

2: since one watch is showing slow, and the other watch is showing fast, but running at the same clock speed, they will NEVER show the absolute correct time. You can wait till the cows come home.

Should this read something like:

1 second per hour slow.....

If you assume both timepieces keep perfect time, and the display is 0:0:0 to 12:12:59, it seems that they could never be the same? Or could they?

On a 12-hour digital display, the numbers would run 0:0:0 to 11:59:59.

Well, no, that isn’t correct.

A digital watch set to display in a 12 hour format would display a range of 12:00:00 (midnight or high noon) to 11:59:59.

A digital watch set to display in a 24 hour format would display the range of 00:00:00 (midnight) to 23:59:59.

So using a 12 hr. clock, it is irrespective of how fast or slow the two watches are without knowing the frequencies of the two time losses. Per minute, per hour per day etc.

Are both watches gaining / losing time equally or does one gain / lose a minute and the other per hour ?

On the assumption that the gains / losses are per Minute both watches will read the same time 12.00 24 hours later.

Not quite clear on the type of watch (digital or analog) in question, but normally for (my watch), or whoever looked first on his/her's own timepiece will always note to have a slower time.. a lag in time.

The time difference can be due to the person's response or reaction time, rather than the type of watch the other person is wearing.. in noting the others actual (your watch) time..

Whenever you and I agree to put our watches side-by-side and look at the same instance together, in my view will determine the time in question.

Since both watches, yours and mine hopefully will continue to keep on ticking, while time passes..

The possible source for this challenge, from Chegg:

8. My watch is 1 second fast per hour and my friend's is 1.5 seconds slow per hour. Right now they show the same time. How many days later will they show the same time again?

At this time, if I insert a credit link to Chegg I get zapped as a spammer.

We both agree to stand here until the show the same time again (12 hr clock)

Question 1: How long will we stand here, waiting for the watches to display the same time?

Answer: How long it takes for us to both reset our watches to the proper time. So around 5 minutes

Question 2: How long until we meet back up again?

Answer 2: After we have reset our watches we can wait a while, then check if our watches are out, and if they are we can then calculate the error and the time taken to give the error, and then calculate a theoretical time when we would come back and have the watches the same again

However this would never happen, because a watch is there to serve the wearer, so, it would be pointless wearing a watch that is out for so long. The watch would be updated or reset to make it in time again

We could then just say that next time we meet we can reset the watches to be in sync again so the answer is: How long until we meet back up again? When ever we decide to meet up next. since we are probably friends and think more of our friendship than a watch

With math's there's mostly right and wrong answer's, but with people there's mostly better or worse solutions

Great puzzle, the watch drift math is deceptively simple until you actually sit down and work it out. Took me a minute but satisfying once it clicks