google finance – Googlefinance in historical mode (WEEKLY): extra rows and not always aligned to fridays

I am trying to use GOOGLEFINANCE function to query the weekly close price of an instrument (SP500, ticker “.INX”), for the last 52 weeks.

I first tried using the following formula:


Where TODAY() in this case corresponds to 31/01/2020 (Thursday).

However, when I look at the results, I see that the following issues:
I get 57 results, instead of the expected 52
There are 8 rows correspond to dates not falling on a friday.
I do not get a result for the nearest friday (25/12/2020).

See first screenshot.enter image description here

I then decided to force the start and end dates passed as arguments to the googlefinance function to fall on a friday:


With this query, if the dates passed to the start or end date fall on a day other than a friday, then the dates are adjusted to the previous friday (workday).

In this case, the results look very similar but shifted one week before. The issues are the same, I get results for dates that do not fall on a friday, and additionally, I do not get a result for the most recent friday (25/12/2020).

One could think, that GOOGLEFINANCE ​adjusts results for those trading days when the stocks are closed, however there are several examples where I get results for a tuesday (28/07/2020), but I also get results for the previous (24/07/2020) and next friday (31/07/2020), and there are no bank holidays in between.
See second screenshot.

enter image description here

I would appreciate your help.

You can also find a link to the sheet here: