Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Excel incorrectly assumes that the year 1900 is a leap year

learn.microsoft.com

Post reply on HN
Print view View original

11–20 of 36 posts

Re: Excel incorrectly assumes that the year 1900 is a leap year

#11

Post by teraflop »

emmelaich wrote: post #9
gerdesj wrote: post #6

Earlier quoted context omitted.

To be fair, that's nowhere near as daft as september, october, november, december. Latin for seven, eight, nine, and ten is: septem, octem, novem, decem. Those are the nineth, 10th, 11th and 12th months. Edit: Whoops, correct eng -> latin nums

You may know this but originally they were 'correct' because the start of the year was March.

Which wouldn't be that weird, except that the earliest Roman calendar started in March and ended in December, having only 10 months!

The Romans were of course well aware that this left a gap of about two months between the end of one year in December, and the beginning of the next year in March. But they just didn't bother counting this period as part of the calendar year. Presumably because there was no agricultural reason to need accurate dates during winter.

Re: Excel incorrectly assumes that the year 1900 is a leap year

#12

Post by a012 »

parenthesis wrote: post #10
darknavi wrote: post #3

> Applies to: Microsoft Excel for Mac 2011, Excel for Microsoft 365 for Mac, Microsoft Office Excel 2003, Microsoft Office Excel 2007, Excel 2010, Excel 2013, Excel 2016

What about Microsoft 366?

Although it is technically possible to correct this behavior so that current versions of Microsoft Copilot 366 is a leap year, the disadvantages of doing so outweigh the advantages.

Re: Excel incorrectly assumes that the year 1900 is a leap year

#13

Post by tom_alexander »

nippoo wrote: post #2

In other "incorrect calendars" bugs, there's the Rockchip RK808 RTC, where the engineers thought that November had 31 days, needing a Linux kernel patch to this day that translates between Gregorian and Rockchip calendars (which are gradually diverging over time). Also one of my favourite kernel patch messages: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin... .

My favorite: For one day all the Microsoft Zunes froze for the entire day, only to recover on their own 24 hours later when the infinite loop in their leap year code had finally resolved: https://web.archive.org/web/20090313105752/http://www.zunebo...

Re: Excel incorrectly assumes that the year 1900 is a leap year

#14

Post by gpm »

etothepii wrote: post #4
darknavi wrote: post #3

> Applies to: Microsoft Excel for Mac 2011, Excel for Microsoft 365 for Mac, Microsoft Office Excel 2003, Microsoft Office Excel 2007, Excel 2010, Excel 2013, Excel 2016

This will never stop as it would require either the reference date to be changed or fir all dates in all saved spreadsheets to be off by one.

Or... A version number that tells excel which convention to use?

I suppose that would make copy and pasting formulas between spreadsheets very mildly error prone though, so it probably won't happen.

Re: Excel incorrectly assumes that the year 1900 is a leap year

#15

Post by caminante »

gerdesj wrote: post #6
nippoo wrote: post #2

In other "incorrect calendars" bugs, there's the Rockchip RK808 RTC, where the engineers thought that November had 31 days, needing a Linux kernel patch to this day that translates between Gregorian and Rockchip calendars (which are gradually diverging over time). Also one of my favourite kernel patch messages: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin... .

To be fair, that's nowhere near as daft as september, october, november, december. Latin for seven, eight, nine, and ten is: septem, octem, novem, decem. Those are the nineth, 10th, 11th and 12th months. Edit: Whoops, correct eng -> latin nums

No? How is it octem and not octo? Does the flat bar accent do something?

>The Latin word for "eight" is octō. [0]

[0] asked google

Re: Excel incorrectly assumes that the year 1900 is a leap year

#16

Post by shakna »

teraflop wrote: post #11
emmelaich wrote: post #9

Earlier quoted context omitted.

You may know this but originally they were 'correct' because the start of the year was March.

Which wouldn't be that weird, except that the earliest Roman calendar started in March and ended in December, having only 10 months! The Romans were of course well aware that this left a gap of about two months between the end of one year in December, and the beginning of the next year in March. But they just didn't bother counting this period as part of the calendar year. Presumably because there was no agricultural…

Numa did try to name and consolidate the winter months, but it wasn't very popular.

The months were for productive seasons, winter for everything else.

Re: Excel incorrectly assumes that the year 1900 is a leap year

#17

Post by _kst_ »

gerdesj wrote: post #6
nippoo wrote: post #2

In other "incorrect calendars" bugs, there's the Rockchip RK808 RTC, where the engineers thought that November had 31 days, needing a Linux kernel patch to this day that translates between Gregorian and Rockchip calendars (which are gradually diverging over time). Also one of my favourite kernel patch messages: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin... .

To be fair, that's nowhere near as daft as september, october, november, december. Latin for seven, eight, nine, and ten is: septem, octem, novem, decem. Those are the nineth, 10th, 11th and 12th months. Edit: Whoops, correct eng -> latin nums

"I hate that SEPTember OCTOber NOVember and DECember aren't the7th, 8th, 9th, and 10th months."

"Whoever f---ed this up should be stabbed."

"I have excellent news for you."

Re: Excel incorrectly assumes that the year 1900 is a leap year

#18

Post by gus_massa »

gpm wrote: post #14
etothepii wrote: post #4

Earlier quoted context omitted.

This will never stop as it would require either the reference date to be changed or fir all dates in all saved spreadsheets to be off by one.

Or... A version number that tells excel which convention to use? I suppose that would make copy and pasting formulas between spreadsheets very mildly error prone though, so it probably won't happen.

There already two date systems, IIRC for compatibility with Macs, I probably read it in the OldNewThing, but I can't finf it. Anyway, it's explained in https://support.microsoft.com/en-us/office/date-systems-in-e...

Re: Excel incorrectly assumes that the year 1900 is a leap year

#19

Post by capitainenemo »

_kst_ wrote: post #17
gerdesj wrote: post #6

Earlier quoted context omitted.

To be fair, that's nowhere near as daft as september, october, november, december. Latin for seven, eight, nine, and ten is: septem, octem, novem, decem. Those are the nineth, 10th, 11th and 12th months. Edit: Whoops, correct eng -> latin nums

"I hate that SEPTember OCTOber NOVember and DECember aren't the7th, 8th, 9th, and 10th months." "Whoever f---ed this up should be stabbed." "I have excellent news for you."

https://old.reddit.com/r/Jokes/comments/m5f6wv/i_hate_that_s...
Post reply on HN