5 ms·

That is a surprising amount of complexity, really makes you glad that ISO ironed out all the details, so when I recently told our development team composed of S

by mikl 7y ago

That is a surprising amount of complexity, really makes you glad that ISO ironed out all the details, so when I recently told our development team composed of Swiss, German, Portuguese and Danish people that we would be going live in week 4 (of 2020), everyone understood just fine. I still find it strange that some countries have not adopted week numbers. Sure, you can say something like "the week of December 21st", but simply saying "week 52" is so much easier, and if you, like many software teams do, work in two week sprints, it saves you from a lot of date math.

savolai 7y ago
I find week numbers very cumbersome to use. Most calendars don't have them by default and most everyday interactions around dates don't involve them. As a result it's a burdensome and unroutined lookup in some arbitrary calendar somewhere just to figure out ballpark distances from current moment. I much prefer date ranges.
- _jal 7y ago
  It is a communicative convention. If you're the only person following a convention, it isn't. At least this is an additive one - unlike imperial/metric, it isn't a unit replacement. Even if you like "better" measures, you may want to stick with local ones. Little story - I noodle around with metalwork, and have some machinery. Because I lived in Europe for a bit, I am comfortable with metric, and metric mental math is so much less error prone that when I was choosing machinery, I went metric. That was a mistake. Everyone I've had in my shop freaks out. All the little rules of thumb and patterns for remembering relations between, say, feed rate to mill spindle speed for a particular alloy go out the window. Reading documentation and how-to texts written in the US puts you right back at doing lots of math in weird bases in your head. And so on. It is fine, I'm happy with my setup. But there are reasons not to pick the "better" method. And those reasons perpetuate the existence of the other ones.
  - blattimwind 7y ago
    > I went metric. That was a mistake. It might be a mistake in the US, but of course machine shops outside the US are all metric - conversely, operating an imperial machine shop might be quite annoying outside the US. > It is fine, I'm happy with my setup. But there are reasons not to pick the "better" method. And those reasons perpetuate the existence of the other ones. Interestingly the US industry didn't switch to metric citing "conversion cost" (in the late 19th / early 20th century). Instead we continue to waste billions every year since: keeping double stock, projects failing (see: space), US engineers struggling with the system everyone else uses (and vice versa, though to a lesser extent, since US-made components and machinery are relatively irrelevant in industry) etc.
    - grawprog 7y ago
      I live in Canada, we use metric, I had to learn imperial when I started at a machine shop. The machines all worked to .0001 inches and we measured our pieces to 1/16" accuracy. Personally, despite using metric all my life and using it for almost everything else i've done. Using imperial and fractions of inches for that kind of work was more intuitive for me and a lot easier to figure out in my head. I find it a lot easier to mentally add fractions than decimals.
      - OldHand2018 7y ago
        > Using imperial and fractions of inches for that kind of work was more intuitive for me and a lot easier to figure out in my head. I find it a lot easier to mentally add fractions than decimals. Imperial fractions also tend to use base-2 numbers as the denominator. I'd be willing to bet that you infrequently saw anything that used thirds or fifths. Most everything would have been halves, quarters, eighths, sixteenths or even thirtyseconds of something.
    - _jal 7y ago
      > Interestingly the US industry didn't switch to metric citing "conversion cost" This isn't in the past - it is an ongoing argument that literally anyone who spends any degree of time in a machine shop gets roped in to. Every machine purchase is a vote on the ongoing argument. Which is why I explicitly called it out - because of a collective action problem in the US, we can't make a simple, obvious efficiency change (which would indeed cause comparatively brief pain for large ongoing payoffs)[1]. It was a mistake for me to switch for the reasons specified. The interesting part is that correct micro-scale choices create a macro-scale problem. Seems to be an ongoing theme of the past couple of decades. [1] If you're not familiar with this, curious why a simple standards issue is well and truly unsolvable, and feeling masochistic you can search Youtube to catch what passes for mainstream political talking heads here making it about "heritage" and how the metric system is part of a UN plot.
- mikl 7y ago
  Depends a lot on your locale. Physical calendars around here always have them, and all decent calendar software has an option to display them. And if you’d grown up with it, it would be a lot more natural. Much like you probably know what month you’re in without checking your watch, I have a pretty good idea what week we’re in, and if someone says they can deliver something in week 8, I instinctively know that’s late February without having to check. So it’s a useful shorthand in many ways.
  - oefrha 7y ago
    > And if you’d grown up with it, it would be a lot more natural. That’s like saying imperial units are more natural than ISO units because you grew up with them. Of course what you grew up with is more natural to you, it doesn’t say much. The problem is not everyone grew up with it, compared to “the week of Dec 21.” Not saying week numbers aren’t useful, I’ve used them to label weekly results in datasets, for instance.
    - rightbyte 7y ago
      You could argue that the "natural" part with using weeks is that the weekends split up your working days, but there is no effect of januari becoming februari and that weeks thus are a more natural unit for planning at work.
    - yitchelle 7y ago
      No, it is natural to us because our working rhythm is based on a week. It just seems logical to think in terms of weeks.
  - majewsky 7y ago
    > all decent calendar software has an option to display them I suppose all those calendar software I've seen over the years ain't true scotsmen.
  - stoicShell 7y ago
    I think it's cultural, acquired indeed. I've pondered on dates and how to divide the year down to how long weeks should be — for way longer than I care to admit. The thing is, we basically need there characters to map dates (it would be easier with a duodecimal/dozenal system for months, but 1-9,A,B works too). Using weeks, we could say that e.g. "23-2" is the second day of week 23, from 01-1 to 52-2 (or 52-3 on leap years). This seems like a good business approach to me. I'd go one step further and map these to Q's, it's 13 weeks for each (13×4 = 52). Which neatly maps to 12 weeks of work + 1 week transition (debrief, brief) between each Q. What's interesting is that we count hours, projects, deadlines usually in week units — e.g. most labor regulations speak of weekly work hours, whereas months are sketchy depending where weekends fall, 28-31 days, etc. So it's easy to think e.g.: we got 3 weeks for this, team of 5, that's 3×5×40 = 600 man-hours. Finally, considering a 5 workdays week (Mon-Fri), you can easily use .2 increments for days: 24.0 for Monday, 24.2 for Tuesday, 24.4 for Wednesday, 24.6 Thursday and 24.8 Friday of the 24th week. What's the use? Well, between e.g. 24.6 and 28.2 you can quickly do the math and get 4.4 = 4 workweeks + 3 days. It may seem like nothing but math on dates has always been hard when it doesn't have to be. We shouldn't need Excel or Google to quickly calculate date differences, number of days since/until, etc.
- gerikson 7y ago
  Here in Sweden, every calendar includes week numbers. You can enable viewing them in Outlook (I guess both ISO weeks and US style week numbering). Due to some school holidays always falling on the same week (Winter holiday on week 9 in Stockholm, for example), they have impact outside workplaces. Schools of course find planning the year in weeks very convenient. This bleeds over into holiday planning at workplaces.
- jcrawfordor 7y ago
  Most calendars in the US sold for "business" use show week numbers on each Sunday since week numbers are often used by people in payroll and finance. So it's not too hard to get a calendar that shows them and I also find it useful for things like working out 2/3 week sprints into the future.
- knorker 7y ago
  > Most calendars don't have them by default Oh? Google calendar and other software I use has them by default.
  - inetknght 7y ago
    I think better said: don't have them _displayed_ by default
    - knorker 7y ago
      Everything I referred to does. ... What else could I have meant?
mongol 7y ago
First Thursday of January is always in week 1. That is actually the only rule needed.
- mikl 7y ago
  The rule is simple, but all the work that led up to the formulation of it wasn’t :)
- Biganon 7y ago
  Why Thursday?
  - scbrg 7y ago
    Presumably because then you know that the majority of week 1 is in the new year.
    - mongol 7y ago
      Yes exactly. Week 1 is the first week where the majority of the days in the week are in the new year. If Thursday is in the new year, so is also Friday, Saturday and Sunday and with those four days in the new year, it is always the majority of the week.
      - cesarb 7y ago
        > If Thursday is in the new year, so is also Friday, Saturday and Sunday and with those four days in the new year, it is always the majority of the week. That's only if you count Sunday as the last day of a week, instead of it being the first day of the following week.
        gerikson 7y ago
        ISO counts Monday as the first day of the week.
defanor 7y ago
> ISO ironed out all the details Not quite: the paywalled standard itself contains bits like "dot or comma" for fractional part separators, which are then interpreted differently. Some software would use a dot (for printing and/or parsing), some would use comma, some would depend on a locale. It also allows to omit time zone (making the time unclear) and is generally quite complex, with implementations being incomplete (or having subtle differences) sometimes. Of course it's better than the zoo of formats, but RFC 3339 (ISO 8601's profile) is considerably better for interoperability, eliminating ambiguities and many options.
baby 7y ago
how am I supposed to know when week 33 is?
- ahartmetz 7y ago
  You enable week numbers in your computer's calendar.
  - baby 7y ago
    interesting, this makes me think of Java that requires an IDE to be usable as a developer.
    - TremendousJudge 7y ago
      If you weren't used to regular calendars you wouldn't know that "August 10" means "about the middle of winter" either
      - baby 7y ago
        August 10 is actually the middle of summer oO EDIT: you are all lying, if christmas movies have taught me anything it is snowing everywhere in the world in december.
        skhagebnsk 7y ago
        Not in the Southern Hemisphere.
        hanche 7y ago
        in the northern hemisphere.
        twojacobtwo 7y ago
        How about for the southern hemisphere?
        yitchelle 7y ago
podnami 7y ago
Week numbers are a staple in many countries calendar systems. In Sweden most school children follow a weekly curriculum for instance. We also mark milestones of pregnancies by week numbers as opposed to trimesters.
- zeroonetwothree 7y ago
  In the US weeks are also used for pregnancies. Trimester is more of an informal thing since it’s so imprecise.
ulfw 7y ago
That's a bad example. Knowing what week 4 is is easy ("End of January"). What's week 27? Or week 43? Without looking at a calendar I can only roughly guestimate.
- mikl 7y ago
  Week numbers are easily compared to your present time. If you are in week 19, and you know you have to finish something by week 27, you can easily calculate how many weeks you have until that time. I don’t need to know what exact dates week 27 is when reasoning about it, for most purposes, I can just do simple math to calculate how many weeks it is away.
BrandoElFollito 7y ago
On the other hand, when I hear "the week of April 9th" I do not have to think a lot about when this is, around which holidays (I am in France :)), the kind of weather we will have, etc. Week 27 requires some compute to place it somewhere in the year.
- grzm 7y ago
  Does the week of April 9th start on a Monday or a Sunday? If you have a shared context, these kinds of things don’t matter as much. Things get hairy when you don’t, and worse when you think you do, but don’t :)

by mikl 7y ago

savolai 7y ago

I find week numbers very cumbersome to use. Most calendars don't have them by default and most everyday interactions around dates don't involve them. As a result it's a burdensome and unroutined lookup in some arbitrary calendar somewhere just to figure out ballpark distances from current moment. I much prefer date ranges.

_jal 7y ago
It is a communicative convention. If you're the only person following a convention, it isn't. At least this is an additive one - unlike imperial/metric, it isn't a unit replacement. Even if you like "better" measures, you may want to stick with local ones. Little story - I noodle around with metalwork, and have some machinery. Because I lived in Europe for a bit, I am comfortable with metric, and metric mental math is so much less error prone that when I was choosing machinery, I went metric. That was a mistake. Everyone I've had in my shop freaks out. All the little rules of thumb and patterns for remembering relations between, say, feed rate to mill spindle speed for a particular alloy go out the window. Reading documentation and how-to texts written in the US puts you right back at doing lots of math in weird bases in your head. And so on. It is fine, I'm happy with my setup. But there are reasons not to pick the "better" method. And those reasons perpetuate the existence of the other ones.
- blattimwind 7y ago
  > I went metric. That was a mistake. It might be a mistake in the US, but of course machine shops outside the US are all metric - conversely, operating an imperial machine shop might be quite annoying outside the US. > It is fine, I'm happy with my setup. But there are reasons not to pick the "better" method. And those reasons perpetuate the existence of the other ones. Interestingly the US industry didn't switch to metric citing "conversion cost" (in the late 19th / early 20th century). Instead we continue to waste billions every year since: keeping double stock, projects failing (see: space), US engineers struggling with the system everyone else uses (and vice versa, though to a lesser extent, since US-made components and machinery are relatively irrelevant in industry) etc.
  - grawprog 7y ago
    I live in Canada, we use metric, I had to learn imperial when I started at a machine shop. The machines all worked to .0001 inches and we measured our pieces to 1/16" accuracy. Personally, despite using metric all my life and using it for almost everything else i've done. Using imperial and fractions of inches for that kind of work was more intuitive for me and a lot easier to figure out in my head. I find it a lot easier to mentally add fractions than decimals.
    - OldHand2018 7y ago
      > Using imperial and fractions of inches for that kind of work was more intuitive for me and a lot easier to figure out in my head. I find it a lot easier to mentally add fractions than decimals. Imperial fractions also tend to use base-2 numbers as the denominator. I'd be willing to bet that you infrequently saw anything that used thirds or fifths. Most everything would have been halves, quarters, eighths, sixteenths or even thirtyseconds of something.
  - _jal 7y ago
    > Interestingly the US industry didn't switch to metric citing "conversion cost" This isn't in the past - it is an ongoing argument that literally anyone who spends any degree of time in a machine shop gets roped in to. Every machine purchase is a vote on the ongoing argument. Which is why I explicitly called it out - because of a collective action problem in the US, we can't make a simple, obvious efficiency change (which would indeed cause comparatively brief pain for large ongoing payoffs)[1]. It was a mistake for me to switch for the reasons specified. The interesting part is that correct micro-scale choices create a macro-scale problem. Seems to be an ongoing theme of the past couple of decades. [1] If you're not familiar with this, curious why a simple standards issue is well and truly unsolvable, and feeling masochistic you can search Youtube to catch what passes for mainstream political talking heads here making it about "heritage" and how the metric system is part of a UN plot.
mikl 7y ago
Depends a lot on your locale. Physical calendars around here always have them, and all decent calendar software has an option to display them. And if you’d grown up with it, it would be a lot more natural. Much like you probably know what month you’re in without checking your watch, I have a pretty good idea what week we’re in, and if someone says they can deliver something in week 8, I instinctively know that’s late February without having to check. So it’s a useful shorthand in many ways.
- oefrha 7y ago
  > And if you’d grown up with it, it would be a lot more natural. That’s like saying imperial units are more natural than ISO units because you grew up with them. Of course what you grew up with is more natural to you, it doesn’t say much. The problem is not everyone grew up with it, compared to “the week of Dec 21.” Not saying week numbers aren’t useful, I’ve used them to label weekly results in datasets, for instance.
  - rightbyte 7y ago
    You could argue that the "natural" part with using weeks is that the weekends split up your working days, but there is no effect of januari becoming februari and that weeks thus are a more natural unit for planning at work.
  - yitchelle 7y ago
    No, it is natural to us because our working rhythm is based on a week. It just seems logical to think in terms of weeks.
- majewsky 7y ago
  > all decent calendar software has an option to display them I suppose all those calendar software I've seen over the years ain't true scotsmen.
- stoicShell 7y ago
  I think it's cultural, acquired indeed. I've pondered on dates and how to divide the year down to how long weeks should be — for way longer than I care to admit. The thing is, we basically need there characters to map dates (it would be easier with a duodecimal/dozenal system for months, but 1-9,A,B works too). Using weeks, we could say that e.g. "23-2" is the second day of week 23, from 01-1 to 52-2 (or 52-3 on leap years). This seems like a good business approach to me. I'd go one step further and map these to Q's, it's 13 weeks for each (13×4 = 52). Which neatly maps to 12 weeks of work + 1 week transition (debrief, brief) between each Q. What's interesting is that we count hours, projects, deadlines usually in week units — e.g. most labor regulations speak of weekly work hours, whereas months are sketchy depending where weekends fall, 28-31 days, etc. So it's easy to think e.g.: we got 3 weeks for this, team of 5, that's 3×5×40 = 600 man-hours. Finally, considering a 5 workdays week (Mon-Fri), you can easily use .2 increments for days: 24.0 for Monday, 24.2 for Tuesday, 24.4 for Wednesday, 24.6 Thursday and 24.8 Friday of the 24th week. What's the use? Well, between e.g. 24.6 and 28.2 you can quickly do the math and get 4.4 = 4 workweeks + 3 days. It may seem like nothing but math on dates has always been hard when it doesn't have to be. We shouldn't need Excel or Google to quickly calculate date differences, number of days since/until, etc.
gerikson 7y ago
Here in Sweden, every calendar includes week numbers. You can enable viewing them in Outlook (I guess both ISO weeks and US style week numbering). Due to some school holidays always falling on the same week (Winter holiday on week 9 in Stockholm, for example), they have impact outside workplaces. Schools of course find planning the year in weeks very convenient. This bleeds over into holiday planning at workplaces.
jcrawfordor 7y ago
Most calendars in the US sold for "business" use show week numbers on each Sunday since week numbers are often used by people in payroll and finance. So it's not too hard to get a calendar that shows them and I also find it useful for things like working out 2/3 week sprints into the future.
knorker 7y ago
> Most calendars don't have them by default Oh? Google calendar and other software I use has them by default.
- inetknght 7y ago
  I think better said: don't have them _displayed_ by default
  - knorker 7y ago
    Everything I referred to does. ... What else could I have meant?

mongol 7y ago

First Thursday of January is always in week 1. That is actually the only rule needed.

mikl 7y ago
The rule is simple, but all the work that led up to the formulation of it wasn’t :)
Biganon 7y ago
Why Thursday?
- scbrg 7y ago
  Presumably because then you know that the majority of week 1 is in the new year.
  - mongol 7y ago
    Yes exactly. Week 1 is the first week where the majority of the days in the week are in the new year. If Thursday is in the new year, so is also Friday, Saturday and Sunday and with those four days in the new year, it is always the majority of the week.
    - cesarb 7y ago
      > If Thursday is in the new year, so is also Friday, Saturday and Sunday and with those four days in the new year, it is always the majority of the week. That's only if you count Sunday as the last day of a week, instead of it being the first day of the following week.
      - gerikson 7y ago
        ISO counts Monday as the first day of the week.

defanor 7y ago

> ISO ironed out all the details Not quite: the paywalled standard itself contains bits like "dot or comma" for fractional part separators, which are then interpreted differently. Some software would use a dot (for printing and/or parsing), some would use comma, some would depend on a locale. It also allows to omit time zone (making the time unclear) and is generally quite complex, with implementations being incomplete (or having subtle differences) sometimes. Of course it's better than the zoo of formats, but RFC 3339 (ISO 8601's profile) is considerably better for interoperability, eliminating ambiguities and many options.

baby 7y ago

how am I supposed to know when week 33 is?

ahartmetz 7y ago
You enable week numbers in your computer's calendar.
- baby 7y ago
  interesting, this makes me think of Java that requires an IDE to be usable as a developer.
  - TremendousJudge 7y ago
    If you weren't used to regular calendars you wouldn't know that "August 10" means "about the middle of winter" either
    - baby 7y ago
      August 10 is actually the middle of summer oO EDIT: you are all lying, if christmas movies have taught me anything it is snowing everywhere in the world in december.
      - skhagebnsk 7y ago
        Not in the Southern Hemisphere.
      - hanche 7y ago
        in the northern hemisphere.
      - twojacobtwo 7y ago
        How about for the southern hemisphere?
      - yitchelle 7y ago

podnami 7y ago

Week numbers are a staple in many countries calendar systems. In Sweden most school children follow a weekly curriculum for instance. We also mark milestones of pregnancies by week numbers as opposed to trimesters.

zeroonetwothree 7y ago
In the US weeks are also used for pregnancies. Trimester is more of an informal thing since it’s so imprecise.

ulfw 7y ago

That's a bad example. Knowing what week 4 is is easy ("End of January"). What's week 27? Or week 43? Without looking at a calendar I can only roughly guestimate.

mikl 7y ago
Week numbers are easily compared to your present time. If you are in week 19, and you know you have to finish something by week 27, you can easily calculate how many weeks you have until that time. I don’t need to know what exact dates week 27 is when reasoning about it, for most purposes, I can just do simple math to calculate how many weeks it is away.

BrandoElFollito 7y ago

On the other hand, when I hear "the week of April 9th" I do not have to think a lot about when this is, around which holidays (I am in France :)), the kind of weather we will have, etc. Week 27 requires some compute to place it somewhere in the year.

grzm 7y ago
Does the week of April 9th start on a Monday or a Sunday? If you have a shared context, these kinds of things don’t matter as much. Things get hairy when you don’t, and worse when you think you do, but don’t :)