function SecondOfTheWeek(const AValue: TDateTime): Cardinal;
unsigned int __fastcall SecondOfTheWeek(System::TDateTime AValue);
Returns the number of seconds between a specified TDateTime value and 12:00:00 A.M. of the first day of the week.
Call SecondOfTheWeek to obtain the number of seconds between AValue and 12:00:00 A.M. on Monday of the week that includes AValue.
Note: SecondOfTheWeek defines the week of AValue according to the ISO 8601 standard. That is, the week starts on Monday and ends on Sunday.