Why are there 52 weeks in a year and not 48 weeks given that there are only 4 weeks per month (4 x 12 = 48)?

Why are there 52 weeks in a year and not 48 weeks given that there are only 4 weeks per month (4 x 12 = 48)?

The question starts with a false premise. Four weeks does not equal a month. Only February has exactly 4 weeks on a non leap year ( it has 29 days on a leap year). Every other month has 2 or 3 days more than 4 weeks. In most cases its practical to estimate that a month is approximately 4 weeks. however, in most cases extending that estimation for 1 year (12 months ) creates too large a gap ( Approximately 4 more weeks ).
That is why a year is better estimated as 52 weeks.

(i) If we would have had 48 weeks per year and 7 days per week, we would have had only 48 x 7 = 336 days in a year instead of 365 days. So it would have become necessary to have elongated the day by 0.6 day since 7.6 x 48 = 364.8 days or to have elongated the day from 24 hours long day to 24 x 7.6 / 7 = 26 hours.

But it was not at all possible to have made a day - few hours shorter or a few hours longer than the average “sunrise to sunrise time” which is 23 hours 56 minutes and 4 seconds. As a matter of fact we had to make it a day of 24 hours not of 23 hours 56 minutes and 4 seconds - the time the hour-needle of our clocks would take to complete two rounds of the clock.

(ii) If we would have had 8 days per week we would have had a year of 48 x 8 = 384 days instead of 365 days. So it would have been necessary to have made a day of 365 x 24 / 384 = 22.8 hours only. As already explained that could have also not been possible.

This is how we ended up having 52 weeks in a year and seven days in a week - not even 52.14 weeks a year.

Of course it would have been more streamlined if we would have opted to have had 13 months in a year and 48 weeks a year since 7 x 13 x 48 = 364 days. In that case, we could have had three years of 364 days each with a leap year of 369 days instead of 366 days but in that case also the leap years would have not been of 48 weeks.

Since moon takes 27.322 days to take one round of the earth we could have had 13 months a year with 28 days per month and we could have had precisely 4 weeks a month a year except in the leap years. Quite possibly it had not struck them that the year could have been distributed in this manner also. They would have perhaps thought of doing so if it would have occurred to them.

I hope now you know why we have 24 hours per day even though it is 23 hours 56 minutes and 4 seconds long, 7 days a week instead of 8 days a week and 12 months a year instead of 13 months a year and 52 weeks a year instead of 48 weeks a year and 365 or 366 days per year even though a year is 365.24219 days long.

P.S.
Since Christians think, 13 is not a lucky number there is no chance they would ever agree to have 13 months of 28 days a month in a year and have 4 weeks of 7 days a week in a month.

One solar year equals 365 and 1/4 days, we cannot change that, no matter who is elected president.

Because, 48 weeks times 7 days per week is 336 days and if the week was extended to 8 days then you would need to account for 384 days. Either way you cannot account for a balanced number of weeks for each month without the season changes occurring in a different month each year. You might try some combination of 7 day and 8 day weeks but that would ultimately be exceptionally confusing.

So you end up stuck with one 28 day month and the days of the week shifting to accommodate the calendar. (Actually all months have 28 days but that is something to be saved for another brain teaser.)

Calendars have always been a bone of contention among different cultures and governments. The basic idea has usually been to make the calendar month’s match lunar months. Since lunar months do not have an even number of days according to when the sun rises and sets, this causes people to shift days around to try and make them match. Not all cultures us 7 day weeks or 4 week months, but for business purposes, that’s almost universally used. Other ways of counting days, weeks, months, and even years are mostly observed in cultural or religious settings.

(i) If we would have had 48 weeks per year and 7 days per week, we would have had only 48 x 7 = 336 days in a year instead of 365 days. So it would have converted needed to have extended the day by 0.6 days since 7.6 x 48 = 364.8 days or to have reached the day from 24 hours long day to 24 x 7.6 / 7 = 26 hours.
But it was not at all feasible to have made a day – a few hours shorter or a few hours larger than the typical “sunrise to sunrise time” which is 23 hours 56 minutes and 4 seconds. We had to give it a day of 24 hours not of 23 hours 56 minutes and 4 seconds – the time the hour-needle of our clocks would take to make two rounds of the watch. Weeks in a Year

(ii) If we had had 8 days per week, we would have had a year of 48 x 8 = 384 days alternately of 365 days. So it would have been required to have made a day of 365 x 24 / 384 = 22.8 hours only. As already explained, that could have also not been reasonable.
This is how we ended up having 52 weeks in a year and seven days in a week – not even 52.14 weeks a year.
Of course, it would have been more smooth if we would have opted to have had 13 months in a year and 48 weeks a year since 7 x 13 x 48 = 364 days. In that case, we could have had three years of 364 days each with a leap year of 369 days somewhat of 366 days but in that case, also the leap years would not have been of 48 weeks. Weeks in a Year

There are 7 days in a week. 4 weeks means 28 days. Also, a month has 28/29 or 30 or 31 days. So, a month has 4 weeks + few days. These few days may range from 0 to 3. There are 12 months in a Gregorian Calendar. These months are:

January has 31 days. It means it has 4 weeks and 3 days.
February has 28 days (29 in case of a leap year). It means it has 4 weeks (or 4 weeks + 1 day in a leap year).
March has 31 days. It means it has 4 weeks and 3 days.
April has 30 days. It means it has 4 weeks and 2 days.
May has 31 days. It means it has 4 weeks and 3 days.
June has 30 days. It means it has 4 weeks and 2 days.
July has 31 days. It means it has 4 weeks and 3 days.
August has 31 days. It means it has 4 weeks and 3 days.
September has 30 days. It means it has 4 weeks and 2 days.
October has 31 days. It means it has 4 weeks and 3 days.
November has 30 days. It means it has 4 weeks and 2 days.
December has 31 days. It means it has 4 weeks and 3 days.
Adding these extra days (3 + 0/1 + 3 + 2 + 3 + 2 + 3 + 3 + 2 + 3 + 2 + 3) we get 29/30 days. These extra days amount to 4 weeks + 1/2 day/s.

So, 1 year or 12 months have 48 weeks + 4 weeks + 1/2 day/s, which would result in 52 weeks +1/2 day/s. This can be crosschecked as 52 weeks have 364 days and when we add 1 or 2 we get 365 (normal year) & 366 (leap year).

(i) In a modern-day calendar, we have 365 days total in a year, which when we divide it by 7 because there are 7 days in a week, it would give you the answer of 52.1428571 weeks.

Even when its leap year, which happens to be occurring only every four years. It would still give us 52 weeks in a year. How? Adding one extra day into the calendar makes it a total of 366 days, which when we divide by the number of days in a week, which is seven, it would still give you 52 weeks.

For the earth to complete its orbit on the Sun, it takes 365 days and 5 hours and 48 minutes to finish. That’s why leap year exists to correct a small margin of error in our annual calendars. To compensate for the extra time, we add one extra day every four years to the calendar to maintain accuracy.

Contrary to what many assume that there are only 48 weeks per year. Why did they assume that? Because they standardized that there are 4 weeks in a month. But that’s not accurate because our calendar sometimes has a 31st date or 30th. In the 4th week of the month, not exactly are there 7 days.

(ii) Quite simply, 4 weeks a month is just an APPROXIMATION.

Think about it, If we said 4 weeks is a month and there are 12 months in a year, then there would be 4×12 = 48 weeks in a year. And also, it would mean 4 weeks = 7*4 days = 28 days.

But most months have 30/31 days! So we’re not counting 2/3 days when we say 4 weeks in a month.

Given this, let’s say we have 6 months in a year with 30 days and 6 months with 31 days, then we are not counting 30–28 = 2 days for 6 months i.e. not counting 26 days = 12 days and 31–28 = 3 days for 6 months i.e. not counting 36 days = 18 days.

So, in total, we are not counting 12+18 days = 30 days = 1 month which approximates as 4 weeks. 52–48 = 4 weeks. That’s where we lose the 4 weeks in our calculation!

(iii) So a month with 31 days actually have 4.42857 weeks. This is rounded to 4.
A month with 30 days actually has 4.28571 weeks. This is rounded to 4
So as you can see we lose approximately 0.3 weeks per month if you just add 4 weeks per month multiply 12 months. ( this is not taking February into account)

Now 365 days of the year divided by 7 days per week is 52.142857 weeks. So even 0.142857 weeks are unaccounted for in a year.

Also, consider that the years are fixed to the number of days for the earth to circumvent the sun. This is fixed and BTW not precisely 365 days but just a little bit more than the 365. We, therefore, have a leap year to make up that discrepancy.

(iv) There are not exactly 4 weeks per month and not exactly 52 weeks per year.

The reason is that the year, month, week, and day are defined by different things, and those things are not exact multiples of each other: the year is defined by the motion of the earth around the sun, the month is roughly based on the motion of the moon around the earth, the day is defined by the rotation of the earth around its own axis, and the 7-day week is a pure convention and corresponds to no natural cycle.

If you used 4-week months, there would be approximately 13 months per year (13×4×7 = 364).