public static DateTime? ParseHttpDate(ICharSequence txt, int start, int end)
{
if (txt is null) { CThrowHelper.ThrowArgumentNullException(CExceptionArgument.txt); }
int length = end - start;
if (0u >= (uint)length)
{
return null;
}
else if (length < 0)
{
CThrowHelper.ThrowArgumentException_CannotHaveEndStart();
}
else if (length > 64)
{
CThrowHelper.ThrowArgumentException_CannotParseMoreThan64Chars();
}
return Formatter().Parse0(txt, start, end);
}