Calendar Confusion

On this Sunday, where the United States has emerged out of the always-argued-about Daylight Saving Time I find myself thinking about time, and more specifically calendaring.

I have to admit a bit of confusion over how to refer to Sunday and how to approach it in my own life. Is it a day of reflection and planning for the upcoming week? Or do I start working on things on Sunday because it is the start of the week? What happened to the weekend?

By tradition it’s part of the two days known as the weekend, or literally, the “week end”. But then things get confusing when we start talking about calendars. In the United States the standard is that the calendar week starts on Sunday. As with units of measurement and weight this is different from the rest of the world (well, most of it anyhow) where the calendar week starts on a Monday, as per the international standard 1.

A quick search of the Internet suggests this is for religious reasons, which while it makes sense in some ways, still doesn’t make much sense to me for a country that professes “separation of church and state”. It seems to me the standard start day of the week would be something that falls under state, not church.

Even more confusing is how do we figure out what week number in the year it is? In the title of this particular post I wanted to include the week number for the week that starts today. But what exactly is that number? By many apps I have on my computer or phone week 46 starts today. The reality is that number is malleable depending (again) on where in the world you are and what rules you are following.

ISO 8601 says that week 1 is “the week with the starting year’s first Thursday in it”. If you’re not following ISO 8601? Wikipedia, in the same ISO 8601 article linked above, states different rules:

  • the week with the first business day in the starting year (considering that Saturdays, Sundays and 1st January are non-working days)
  • the week with 4 January in it
  • the first week with the majority (four or more) of its days in the starting year
  • the week starting with the Monday in the period 29 December - 4 January

My head is spinning. Would you like to be more confused? Again per Wikipedia:

As a consequence, if 1 January is on a Monday, Tuesday, Wednesday or Thursday, it is in week 01. If 1 January is on a Friday, Saturday or Sunday, it is in week 52 or 53 of the previous year (there is no week 00). 28 December is always in the last week of its year.

Depending on the rules there can be a week 53 for the previous year!

I’ve decided to forego adding a week number on my posts for now so as to avoid confusion with a potentially international audience. Have a good rest of your weekend everyone! 😀


  1. Don’t even get me started on units of measure where the United States follows the imperial standard for most things while then having 2-liter bottles of soda in the stores. ↩︎

Jason Kratz @jasonekratz