Math Is Fun Forum

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Find Time

The current time is 12 pm CST. What time (CST) will it be 12,997 hours from now?

Let me see.

There are 24 hours in a day.

Must I divide 12,997 hours by 24 hours?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,637

Re: Find Time

Yes but disregard the whole number of days, it's the remainder you are interested in.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Find Time

Yes but disregard the whole number of days, it's the remainder you are interested in.

Bob

12,997/24 = 541.54166666667

What is next?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,637

Re: Find Time

That's 541 complete days and a decimal fraction left over.

Subtract the 541 and multiply the fraction by 24 to change it back to hours. Then you can count on those many hours to get the new time.

Note about the use of pm. It has become common for people to call 12 noon by the new name of 12 pm. This is nonsense. pm is an abbreviation of the Latin phrase post meridian. Meridian is the Latin for noon so post meridian means after-noon. 12 hours after the meridian means midnight! I was staying at a hotel that said the fire alarm was to be tested at 12pm. Did they really mean midnight? I think a lot of guests would not be happy to have the alarm go off then. 

So, personally, I only use noon and midnight and shun this stupid habit of saying 12pm

That said it's probably what the question means

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Find Time

That's 541 complete days and a decimal fraction left over.

Subtract the 541 and multiply the fraction by 24 to change it back to hours. Then you can count on those many hours to get the new time.

Note about the use of pm. It has become common for people to call 12 noon by the new name of 12 pm. This is nonsense. pm is an abbreviation of the Latin phrase post meridian. Meridian is the Latin for noon so post meridian means after-noon. 12 hours after the meridian means midnight! I was staying at a hotel that said the fire alarm was to be tested at 12pm. Did they really mean midnight? I think a lot of guests would not be happy to have the alarm go off then. 

So, personally, I only use noon and midnight and shun this stupid habit of saying 12pm

That said it's probably what the question means

Bob

Very cool reply. I will take it from here.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,893

Re: Find Time

Hi Bob;

...pm is an abbreviation of the Latin phrase post meridian. Meridian is the Latin for noon so post meridian means after-noon...

Down here in Australia I learnt to use the Latin meridiem, not meridian, with the latter being more commonly a geographical term probably derived from the French méridien. See here: Grammarphobia: Ante meridiem or antemeridian?

12 hours after the meridian means midnight! I was staying at a hotel that said the fire alarm was to be tested at 12pm. Did they really mean midnight? I think a lot of guests would not be happy to have the alarm go off then. 

So, personally, I only use noon and midnight and shun this stupid habit of saying 12pm

This is from Wikipedia's '12-hour clock' article, about halfway down the page under the heading 'Confusion at noon and midnight':
     "It is not always clear what times "12:00 a.m." and "12:00 p.m." denote. From the Latin words meridies (midday), ante (before) and post (after), the term ante meridiem (a.m.) means before midday and post meridiem (p.m.) means after midday. Since "noon" (midday, meridies (m.)) is neither before nor after itself, the terms a.m. and p.m. do not apply."

Last edited by phrontister (2024-05-06 17:47:46)

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