#Free pascal convert tdatetime to string plus#

? 138 Latin capital letter S with caron Latin Extended-A ? 136 Modifier letter circumflex accent Spacing Modifier Letters ? 133 Horizontal ellipsis General Punctuation ? 132 Double low-9 quotation mark General Punctuation ? 131 Latin small letter f with hook Latin Extended-B ? 130 Single low-9 quotation mark General Punctuation AnsiChar types are exactly one byte in size, and can hold any of the characters in the Ansi character set. Single character variables hold a single character of text. We'll cover the character and string types in turn, and then look at some of the large range of string processing routines provided by the Delphi run time library. Str7 : WideString // Holds strings of WideChar's of any size desired Str6 : AnsiString // Holds strings of AnsiChar's any size desired Str5 : String // Holds strings of Char's of any size desired

Str4 : ShortString // Holds a string of up to 255 Char's Str3 : AnsiChar // Holds a single character, small alphabet Str2 : WideChar // Holds a single character, International alphabet Str1 : Char // Holds a single character, small alphabet Here are the different text types in Delphi: A letter is stored in a single character variable type, such as Char, and words and sentences stored in string types, such as String. These can be used to store and display such things as user details, screen titles and so on. Like many other languages, such as VBA and Java, Delphi allows you to store letters, words, and sentences in single variables. Learn to program in Pascal - online education course So with that, this: cout << setprecision(17) << convert(convert(37838.Delphi Basics : Strings and characters Delphi Basics Here's a very simple way to do it using my free, open-source, header-only C++20 chrono preview library (works with C++11/14/17): #include 'date/date.h' I'm not sure if std::round() produces exactly the same result as Delphi's System::Round() for all values. Note my comment in DateTimeToTimeStamp(). _int64 Result = SecondsBetween(UnixDateDelta, AValue)

_int64 DateTimeToUnix(const TDateTime AValue) Return std::abs(DateTimeToMilliseconds(ANow) - DateTimeToMilliseconds(AThen)) / MSecsPerSec _int64 SecondsBetween(const TDateTime ANow, const TDateTime AThen) Return (_int64(LTimeStamp.Date) * MSecsPerDay) + LTimeStamp.Time TTimeStamp LTimeStamp = DateTimeToTimeStamp(ADateTime) _int64 DateTimeToMilliseconds(const TDateTime ADateTime) Result.Time = std::abs(LTemp) % IMSecsPerDay _int64 LTemp = std::round(DateTime * FMSecsPerDay) // <- this might require tweaking! TTimeStamp DateTimeToTimeStamp(TDateTime DateTime)

#Free pascal convert tdatetime to string plus#

Int Date // One plus number of days since Int Time // Number of milliseconds since midnight #define DateDelta 693594 // Days between and #define UnixDateDelta 25569 // Days between TDateTime basis () and Unix time_t basis () #define MSecsPerDay (SecsPerDay * MSecsPerSec) #define SecsPerHour (SecsPerMin * MinsPerHour) #define SecsPerDay (MinsPerDay * SecsPerMin) #define MinsPerDay (HoursPerDay * MinsPerHour) The current algorithm looks more like this now (translated to C++ from the original Pascal): #include The algorithm you have shown is how the RTL used to convert a TDateTime to a Unix timestamp many years ago, but that is not how it does so anymore. Since you are trying to do this from outside the RTL, you will need to implement the relevant algorithms in your code. Modern TDateTime operations do a round-trip through TTimeStamp now to avoid that. The RTL stopped using floating-point arithmetic on TDateTime years ago due to subtle precision loss. TDateTime has milliseconds precision, and there are 86400000 milliseconds in a day, so.

So you are encountering a rounding issue, which is exactly what you have to watch out for. Using raw math involving more than just whole days can be a little tricky, since floating-point math is inaccurate.ДЇor instance, 0.001388888886 is not exactly 00:02:00, it is closer to 00:01:59.999. In a TDateTime, the integral portion is the number of days from December 30 1899, and the fractional portion is the time of day from 00:00:00.000. The Delphi/C++Builder RTL has a DateTimeToUnix() function for this exact purpose.