System Time-utils for Inno Setup
function IsLeapYear(const AYear: Integer): Boolean;
procedure ClearSystemTime(var ASystemTime: SYSTEMTIME);
function MonthLength(const AYear, AMonth: Integer): Integer;
function InitSystemTime(const AYear, AMonth, ADay, AHour, AMinute, ASecond, AMillisecond: WORD): SYSTEMTIME;
function DecMonth(const ATime: SYSTEMTIME; const AMonthsToDec: Integer): SYSTEMTIME;
function SameSystemTime(const ASystemTime1, ASystemTime2: SYSTEMTIME): Boolean;
function SystemTimeGreater(const ASystemTime1, ASystemTime2: SYSTEMTIME): Boolean;
function CompareSystemTime(const ASystemTime1, ASystemTime2: SYSTEMTIME): Integer;
function GetSortableTimeStampStr(const ATimeStamp: SYSTEMTIME): string;