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Falsehoods programmers believe about time

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131–140 of 212 posts

Re: Falsehoods programmers believe about time

#131

Post by not2b »

kristopolous wrote: post #104

The "opportunity for bugs" I didn't realize until I was over 10 years into my professional career: 10 AM 11 AM 12 PM 01 PM 02 PM 03 PM I see large software systems for things like airlines and trains sometimes make this mistake, for instance a 1 hour trip on a ticket that says "11:30AM - 12:30AM" which is actually negative 11 hours. I have a collection of photos somewhere of every time I've caught it. If I could chan…

I missed a plane flight once because an admin for the company I was working with booked a midnight flight accidentally and I thought it was at noon (I think she thought so as well). I think it was in the 90s sometime.

Re: Falsehoods programmers believe about time

#132

Post by fragmede »

mindcrime wrote: post #125
lenova wrote: post #98

Earlier quoted context omitted.

First they came for the Special Hats, but I did not speak out -- because I was hatless...

Grandpa, tell me a story about the Time Hat Wars Well sonnie-boy, listen up... it all started on 01-01-1970...

Clearly ISO 8601 didn't win in the time hat wars.

Re: Falsehoods programmers believe about time

#133

Post by gsich »

kristopolous wrote: post #104

The "opportunity for bugs" I didn't realize until I was over 10 years into my professional career: 10 AM 11 AM 12 PM 01 PM 02 PM 03 PM I see large software systems for things like airlines and trains sometimes make this mistake, for instance a 1 hour trip on a ticket that says "11:30AM - 12:30AM" which is actually negative 11 hours. I have a collection of photos somewhere of every time I've caught it. If I could chan…

am/pm users have lost their sanity.

Re: Falsehoods programmers believe about time

#134

Post by decebalus1 »

Ugh.. I personally hate these lists. Absolutely no value added, nobody is going to remember these, they're gonna learn them the hard way and most importantly, if they don't work directly with the timekeeping infrastructure, probably never. And if they do work on the timekeeping infra, they likely know all of this.

Sure, you might run into some quirk at some point in your career but they will end up being just another weird war story.

I worked directly with NTP. The nitty-gritty details and the leap second smears and all of that, for an absolutely huge network and I find this list patronizing, smug and worthless. It's some sort of intellectual masturbation or just another instance of https://news.ycombinator.com/item?id=32335165.

Re: Falsehoods programmers believe about time

#135

Post by Retr0id »

donatj wrote: post #121

> The system clock will always be set to the correct local time. I work on a sometimes offline educational product for children. Kids for some reason love to mess with their system clocks. The hoops we've tried jumping through to get a reasonable time frame of events from iPads that were offline for any period of time is hilarious. We gave up, and if the time of events is unreasonable, we just shift the entire set wa…

> Kids for some reason love to mess with their system clocks.

There are plenty of mobile games that will time-gate in-game rewards (e.g. wait x hours to unlock y). Often, messing with the system clock skips these delays. You're welcome.

Re: Falsehoods programmers believe about time

#136

Post by IncRnd »

alexfoo wrote: post #101
flir wrote: post #80

Earlier quoted context omitted.

Your symbols of office shall be a blinking 12:00 and the date 01-01-1970. Wait. In fact, if you weren't born on 01-01-1970, you can't be Time Druid. Sorry.

Do you mean 01-01-1970 or 01-01-1970?

Don't worry. The Druid will handle that.

Re: Falsehoods programmers believe about time

#137

Post by IncRnd »

donatj wrote: post #121

> The system clock will always be set to the correct local time. I work on a sometimes offline educational product for children. Kids for some reason love to mess with their system clocks. The hoops we've tried jumping through to get a reasonable time frame of events from iPads that were offline for any period of time is hilarious. We gave up, and if the time of events is unreasonable, we just shift the entire set wa…

> Kids for some reason love to mess with their system clocks.

They are cheating at games!

Re: Falsehoods programmers believe about time

#138

Post by IncRnd »

SwiftyBug wrote: post #33

> A week (or a month) always begins and ends in the same year Okay, of course a week can begin in an year and end in the next, but how exactly would a month not begin and end in the same year?

I think they are talking about the End Of Period for a month. Whatever batch or closeout type processing happens during that time period can flow into the next year, despite it being flagged/tagged/marked with the last month of the prior year. So, be careful with using dates! (unless you are a Time Druid)

It could also be a reference to the start of the calendar, but that isn't bound to happen again.... Well, unless it does.

Then, on the other hand (because Time is funky that way) your time may not be the same as my time, since we could be in different time zones.

Re: Falsehoods programmers believe about time

#139

Post by _carbyau_ »

account-5 wrote: post #95
NegativeLatency wrote: post #77

Earlier quoted context omitted.

Something very similar already exists (in theory): https://en.wikipedia.org/wiki/International_Fixed_Calendar Kodak used to run on this calendar.

I was going to mention this. 13 months each with 28 days.

bye bye Halloween...

Re: Falsehoods programmers believe about time

#140

Post by gweinberg »

Obviously nobody believes most of these falsehoods. Presumably the op means a lot of programmers create bugs that seem t imply programmers believe these falsehoods.

But this one jumped out at me: "Any 24-hour period will always begin and end in the same day". It would be a lot more plausible if "always" were replaced with "never". Add 24 hours to a time, and it will (almost) always be the next day.

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