(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.
(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.
Because moon takes 27.322 days to make one round of the earth, we could have had 13 months a year with 28 days per month, and we could have had exactly 4 weeks a month a year but in the leap years. Quite likely it had not hit them that the year could have been given in this manner also. They would have maybe thought of doing so if it would have happened 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 alternatively 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 also though a year is 365.24219 days long.
Since Christians believe, 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.