On what day does the week start?

As I am Portuguese, I was used to having Monday being the start of the week, so it is a bit odd having it being Sunday, here, in Canada and the US.

Second shift isn't too bad. If you can wind down quickly to get to sleep, most of the next day is yours, and having mid week days off you can get lots done without trying to get things done in a crowd as on the weekend.

After my bout with southern swing we went to 3 on 3 off alternating between days/nights, 12 hour shifts. I did that for many years and liked it. I far preferred night shift and my shift mate and I would swap our disliked shifts. He got my day shifts and I took his nights. We could do that for about a month before my wife decided she'd had enough of not seeing me. I loved having a stable sleep schedule for that month even though I was sleeping days. But the room was fully blacked out with aluminum foil on the window glass, heavy black curtains inside that and a white noise machine playing. I'd get home at 0700 thereabouts, stay up for a few hours, all shades and curtains pulled so that I didn't see sunlight, and by 10ish hit the sack. The alarm would wake me for my next nights shift. Did that for 3 days, then 3 days off where I just stayed on modified night shift. The problem came in when getting ready for day shift as happened for most of the year. When I was younger I would just stay up cold turkey to reset my internal clock. But as I aged that became much harder to do so I got a day job. I look at the folks I worked with and they all look 20 years older than their actual age, so I must have played it right and got off shift work when I did. They made more $ than I did, but at what cost? Shift work takes years off of ones life.

As I am Portuguese, I was used to having Monday being the start of the week, so it is a bit odd having it being Sunday, here, in Canada and the US.

Because I am native to the United States, my problem is the exact opposite of yours, celestino.  Each year, when I visit my friend in Scotland, she and I usually go on to the Continent for a few days and I used to look for a small desk calendar with pictures of the place we visited.  The months and days of the week in a foreign language on the calendar I always enjoyed but I could simply never get used to the week starting on a Monday, instead of a Sunday.  It threw me off every time I glanced at the calendar.  Sadly, I now get said desk calendar from the U.S. Canada, or, occasionally, the U.K. and most lack interesting pictures.

Growing up, work and school started on Monday, and so did the week. Now I'm retired, and I don't think as much in terms of weeks.

What day is the start of the week or what day is the first day of the week? The two are not necessarily the same thing.

Sunday was the day of the Roman god Sol Invictus (i.e. the sun), the first day of the week and a day of rest for the Romans. The sabbath, the seventh day and the day of rest, was Saturday for the Jews and later the Christians. Sunday was therefore the first day of their new week also, as that was the day creation started. Judaism was tolerated by the Romans, but Christianity was not. It was therefore convenient for Christians to be mistaken for Jews. This was definitely not the case after the Jewish rebellions in 70 A.D. and 135 A.D. For the Christians, observing the sabbath on Sunday helped them blend in with the pagan Romans, distance themselves from the Jews, and avoid persecution.

The Roman emperor Constantine, a worshipper of Sol Invictus, legalized Christianity for the first time. A few years later, he also created a law requiring people to observe Sunday as a day of rest, as it was the sun's day. The Roman Church then made Sunday the official day of rest and the sabbath. For Christians, and later Rome itself when both Constantine and it became Christian, Monday then became the first day of the new week. That is why calendars were traditionally arranged as Sun - Mon - Tue - Wed - Thu - Fri - Sat, even though most people have long seen Monday as the first day of the week. This notion was further reinforced when people started getting Saturdays off, and weekends became a dividing point between one week and the next.

Because I am native to the United States, my problem is the exact opposite of yours, celestino.  Each year, when I visit my friend in Scotland, she and I usually go on to the Continent for a few days and I used to look for a small desk calendar with pictures of the place we visited.  The months and days of the week in a foreign language on the calendar I always enjoyed but I could simply never get used to the week starting on a Monday, instead of a Sunday.  It threw me off every time I glanced at the calendar.  Sadly, I now get said desk calendar from the U.S. Canada, or, occasionally, the U.K. and most lack interesting pictures.

Here ya go:

https://store.almanac.com/calendars/
http://gavrilisphotography.com/calendars.html

Because I am native to the United States, my problem is the exact opposite of yours, celestino.  Each year, when I visit my friend in Scotland, she and I usually go on to the Continent for a few days and I used to look for a small desk calendar with pictures of the place we visited.  The months and days of the week in a foreign language on the calendar I always enjoyed but I could simply never get used to the week starting on a Monday, instead of a Sunday.  It threw me off every time I glanced at the calendar.  Sadly, I now get said desk calendar from the U.S. Canada, or, occasionally, the U.K. and most lack interesting pictures.

Here ya go:

https://store.almanac.com/calendars/
http://gavrilisphotography.com/calendars.html

Thanks Tbone but these weren't what I was looking for.  I found what I wanted on Amazon, without pictures, unfortunately.