Here is a nice trick you can use to figure this out...
Create a blank report with wizard, export it do RDP file and open it in Visual Studio. Inspect created datasets, one of them is called "DSNumberAndCurrencyInfo".
This is the query behind that dataset.
SELECT
DateFormat, DateFormat + ' ' + TimeFormat AS DateTimeFormat,
NumberLanguageCode, CalendarType,
NumberFormat_0_Precision, NumberFormat_1_Precision,
NumberFormat_2_Precision, NumberFormat_3_Precision,
NumberFormat_4_Precision, NumberFormat_5_Precision,
CurrencyFormat_0_Precision, CurrencyFormat_1_Precision,
CurrencyFormat_2_Precision, CurrencyFormat_3_Precision,
CurrencyFormat_4_Precision, CurrencyFormat_5_Precision
FROM
dbo.fn_GetFormatStrings()
It means that there is a DB function available that will tell you various format setting of the user that executed the function.
You could also dig deeper and open the function, but you probably will not need to.