GetTimeFormatW

// KERNEL32.dll  (Unicode / -W)
#include <windows.h>

INT GetTimeFormatW(
    DWORD Locale,
    DWORD dwFlags,
    const SYSTEMTIME* lpTime,   // optional
    LPCWSTR lpFormat,   // optional
    LPWSTR lpTimeStr,   // optional
    INT cchTime
);

<DllImport("KERNEL32.dll", CharSet:=CharSet.Unicode, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function GetTimeFormatW(
    Locale As UInteger,   ' DWORD
    dwFlags As UInteger,   ' DWORD
    lpTime As IntPtr,   ' SYSTEMTIME* optional
    <MarshalAs(UnmanagedType.LPWStr)> lpFormat As String,   ' LPCWSTR optional
    <MarshalAs(UnmanagedType.LPWStr)> lpTimeStr As System.Text.StringBuilder,   ' LPWSTR optional, out
    cchTime As Integer   ' INT
) As Integer
End Function

' Locale : DWORD
' dwFlags : DWORD
' lpTime : SYSTEMTIME* optional
' lpFormat : LPCWSTR optional
' lpTimeStr : LPWSTR optional, out
' cchTime : INT
Declare PtrSafe Function GetTimeFormatW Lib "kernel32" ( _
    ByVal Locale As Long, _
    ByVal dwFlags As Long, _
    ByVal lpTime As LongPtr, _
    ByVal lpFormat As LongPtr, _
    ByVal lpTimeStr As LongPtr, _
    ByVal cchTime As Long) As Long
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

GetTimeFormatW = ctypes.windll.kernel32.GetTimeFormatW
GetTimeFormatW.restype = ctypes.c_int
GetTimeFormatW.argtypes = [
    wintypes.DWORD,  # Locale : DWORD
    wintypes.DWORD,  # dwFlags : DWORD
    ctypes.c_void_p,  # lpTime : SYSTEMTIME* optional
    wintypes.LPCWSTR,  # lpFormat : LPCWSTR optional
    wintypes.LPWSTR,  # lpTimeStr : LPWSTR optional, out
    ctypes.c_int,  # cchTime : INT
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
GetTimeFormatW = Fiddle::Function.new(
  lib['GetTimeFormatW'],
  [
    -Fiddle::TYPE_INT,  # Locale : DWORD
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_VOIDP,  # lpTime : SYSTEMTIME* optional
    Fiddle::TYPE_VOIDP,  # lpFormat : LPCWSTR optional
    Fiddle::TYPE_VOIDP,  # lpTimeStr : LPWSTR optional, out
    Fiddle::TYPE_INT,  # cchTime : INT
  ],
  Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "kernel32")]
extern "system" {
    fn GetTimeFormatW(
        Locale: u32,  // DWORD
        dwFlags: u32,  // DWORD
        lpTime: *const SYSTEMTIME,  // SYSTEMTIME* optional
        lpFormat: *const u16,  // LPCWSTR optional
        lpTimeStr: *mut u16,  // LPWSTR optional, out
        cchTime: i32  // INT
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("KERNEL32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern int GetTimeFormatW(uint Locale, uint dwFlags, IntPtr lpTime, [MarshalAs(UnmanagedType.LPWStr)] string lpFormat, [MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder lpTimeStr, int cchTime);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_GetTimeFormatW' -Namespace Win32 -PassThru
# $api::GetTimeFormatW(Locale, dwFlags, lpTime, lpFormat, lpTimeStr, cchTime)

#uselib "KERNEL32.dll"
#func global GetTimeFormatW "GetTimeFormatW" wptr, wptr, wptr, wptr, wptr, wptr
; GetTimeFormatW Locale, dwFlags, varptr(lpTime), lpFormat, varptr(lpTimeStr), cchTime   ; 戻り値は stat
; Locale : DWORD -> "wptr"
; dwFlags : DWORD -> "wptr"
; lpTime : SYSTEMTIME* optional -> "wptr"
; lpFormat : LPCWSTR optional -> "wptr"
; lpTimeStr : LPWSTR optional, out -> "wptr"
; cchTime : INT -> "wptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "KERNEL32.dll"
#cfunc global GetTimeFormatW "GetTimeFormatW" int, int, var, wstr, var, int
; res = GetTimeFormatW(Locale, dwFlags, lpTime, lpFormat, lpTimeStr, cchTime)
; Locale : DWORD -> "int"
; dwFlags : DWORD -> "int"
; lpTime : SYSTEMTIME* optional -> "var"
; lpFormat : LPCWSTR optional -> "wstr"
; lpTimeStr : LPWSTR optional, out -> "var"
; cchTime : INT -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; INT GetTimeFormatW(DWORD Locale, DWORD dwFlags, SYSTEMTIME* lpTime, LPCWSTR lpFormat, LPWSTR lpTimeStr, INT cchTime)
#uselib "KERNEL32.dll"
#cfunc global GetTimeFormatW "GetTimeFormatW" int, int, var, wstr, var, int
; res = GetTimeFormatW(Locale, dwFlags, lpTime, lpFormat, lpTimeStr, cchTime)
; Locale : DWORD -> "int"
; dwFlags : DWORD -> "int"
; lpTime : SYSTEMTIME* optional -> "var"
; lpFormat : LPCWSTR optional -> "wstr"
; lpTimeStr : LPWSTR optional, out -> "var"
; cchTime : INT -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	procGetTimeFormatW = kernel32.NewProc("GetTimeFormatW")
)

// Locale (DWORD), dwFlags (DWORD), lpTime (SYSTEMTIME* optional), lpFormat (LPCWSTR optional), lpTimeStr (LPWSTR optional, out), cchTime (INT)
r1, _, err := procGetTimeFormatW.Call(
	uintptr(Locale),
	uintptr(dwFlags),
	uintptr(lpTime),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpFormat))),
	uintptr(lpTimeStr),
	uintptr(cchTime),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function GetTimeFormatW(
  Locale: DWORD;   // DWORD
  dwFlags: DWORD;   // DWORD
  lpTime: Pointer;   // SYSTEMTIME* optional
  lpFormat: PWideChar;   // LPCWSTR optional
  lpTimeStr: PWideChar;   // LPWSTR optional, out
  cchTime: Integer   // INT
): Integer; stdcall;
  external 'KERNEL32.dll' name 'GetTimeFormatW';

result := DllCall("KERNEL32\GetTimeFormatW"
    , "UInt", Locale   ; DWORD
    , "UInt", dwFlags   ; DWORD
    , "Ptr", lpTime   ; SYSTEMTIME* optional
    , "WStr", lpFormat   ; LPCWSTR optional
    , "Ptr", lpTimeStr   ; LPWSTR optional, out
    , "Int", cchTime   ; INT
    , "Int")   ; return: INT

●GetTimeFormatW(Locale, dwFlags, lpTime, lpFormat, lpTimeStr, cchTime) = DLL("KERNEL32.dll", "int GetTimeFormatW(dword, dword, void*, char*, char*, int)")
# 呼び出し: GetTimeFormatW(Locale, dwFlags, lpTime, lpFormat, lpTimeStr, cchTime)
# Locale : DWORD -> "dword"
# dwFlags : DWORD -> "dword"
# lpTime : SYSTEMTIME* optional -> "void*"
# lpFormat : LPCWSTR optional -> "char*"
# lpTimeStr : LPWSTR optional, out -> "char*"
# cchTime : INT -> "int"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。