2025-12-12 04:09 UTC+0100 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)

* include/harbour.hbx
  * src/harbour.def
  * src/rtl/dateshb.c
    + added new PRG function which converts UTC time to local time:
          hb_UTCToTS( <tUTCTime> [, @<lUTCOffset> ) -> <tLocalTime>

  * include/hbdate.h
  * src/harbour.def
  * src/common/hbdate.c
    + added new C function which converts UTC time to local time:
         double hb_timeUTCToLocal( double dTimeStamp, int * piUTCOffset );

ChangeLog.txt

@@ -7,6 +7,19 @@
    Entries may not always be in chronological/commit order.
    See license at the end of file. */
 
+2025-12-12 04:09 UTC+0100 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
+  * include/harbour.hbx
+  * src/harbour.def
+  * src/rtl/dateshb.c
+    + added new PRG function which converts UTC time to local time:
+          hb_UTCToTS( <tUTCTime> [, @<lUTCOffset> ) -> <tLocalTime>
+
+  * include/hbdate.h
+  * src/harbour.def
+  * src/common/hbdate.c
+    + added new C function which converts UTC time to local time:
+         double hb_timeUTCToLocal( double dTimeStamp, int * piUTCOffset );
+
 2025-12-11 00:15 UTC+0100 Aleksander Czajczynski (hb fki.pl)
   * src/vm/macro.c
     * workaround MinGW/GCC 15+ excessive diagnostics in hb_macroTextSymbol()

include/harbour.hbx

@@ -922,6 +922,7 @@ DYNAMIC hb_UserName
 DYNAMIC hb_UStuff
 DYNAMIC hb_USubStr
 DYNAMIC hb_UTCOffset
+DYNAMIC hb_UTCToTS
 DYNAMIC hb_utf8Asc
 DYNAMIC hb_utf8At
 DYNAMIC hb_utf8Chr

include/hbdate.h

@@ -104,6 +104,7 @@ extern HB_EXPORT void   hb_timeStampGet( long * plJulian, long * plMilliSec );
 
 extern HB_EXPORT long   hb_timeUTCOffset( void ); /* in seconds */
 extern HB_EXPORT double hb_timeLocalToUTC( double dTimeStamp );
+extern HB_EXPORT double hb_timeUTCToLocal( double dTimeStamp, int * piUTCOffset );
 extern HB_EXPORT long hb_timeStampUTCOffset( int iYear, int iMonth, int iDay,
                                              int iHour, int iMinutes, int iSeconds );
 

src/common/hbdate.c

@@ -495,7 +495,7 @@ char * hb_timeStr( char * szTime, long lMilliSec )
 
 HB_BOOL hb_timeStrGetUTC( const char * szTime,
                           int * piHour, int * piMinutes,
-                          int * piSeconds, int * piMSec, int *piUTCOffset )
+                          int * piSeconds, int * piMSec, int * piUTCOffset )
 {
    int iHour, iMinutes, iSeconds, iMSec, iUTCOffset, iBlocks;
    HB_BOOL fValid;
@@ -1180,6 +1180,86 @@ double hb_timeLocalToUTC( double dTimeStamp )
                                  iHour, iMinutes, iSeconds ) / HB_SECONDS_PER_DAY;
 }
 
+double hb_timeUTCToLocal( double dTimeStamp, int * piUTCOffset )
+{
+   double dLocal;
+
+#if defined( HB_OS_WIN )
+   {
+      typedef BOOL ( WINAPI * P_SYSTEMTIMETOTZSPECIFICLOCALTIME )( LPTIME_ZONE_INFORMATION, LPSYSTEMTIME, LPSYSTEMTIME );
+
+      static HB_BOOL s_fInit = HB_TRUE;
+      static P_SYSTEMTIMETOTZSPECIFICLOCALTIME s_pSystemTimeToTzSpecificLocalTime = NULL;
+
+      int iYear, iMonth, iDay, iHour, iMinutes, iSeconds, iMSec;
+
+      hb_timeStampUnpack( dTimeStamp,
+                          &iYear, &iMonth, &iDay,
+                          &iHour, &iMinutes, &iSeconds, &iMSec );
+      if( s_fInit )
+      {
+         HMODULE hModule = GetModuleHandle( TEXT( "kernel32" ) );
+         if( hModule )
+            s_pSystemTimeToTzSpecificLocalTime = ( P_SYSTEMTIMETOTZSPECIFICLOCALTIME )
+               HB_WINAPI_GETPROCADDRESS( hModule, "SystemTimeToTzSpecificLocalTime" );
+         s_fInit = HB_FALSE;
+      }
+
+      if( s_pSystemTimeToTzSpecificLocalTime )
+      {
+         SYSTEMTIME lt, st;
+
+         st.wYear         = ( WORD ) iYear;
+         st.wMonth        = ( WORD ) iMonth;
+         st.wDay          = ( WORD ) iDay;
+         st.wHour         = ( WORD ) iHour;
+         st.wMinute       = ( WORD ) iMinutes;
+         st.wSecond       = ( WORD ) iSeconds;
+         st.wMilliseconds = ( WORD ) iMSec;
+         st.wDayOfWeek    = 0;
+
+         if( s_pSystemTimeToTzSpecificLocalTime( NULL, &st, &lt ) )
+         {
+            dLocal = hb_timeStampPack( lt.wYear, lt.wMonth, lt.wDay,
+                                       lt.wHour, lt.wMinute, lt.wSecond,
+                                       lt.wMilliseconds );
+         }
+         else
+            dLocal = dTimeStamp + ( double )
+                     hb_timeStampUTCOffset( iYear, iMonth, iDay,
+                              iHour, iMinutes, iSeconds ) / HB_SECONDS_PER_DAY;
+      }
+      else
+         dLocal = dTimeStamp + ( double )
+                  hb_timeStampUTCOffset( iYear, iMonth, iDay,
+                              iHour, iMinutes, iSeconds ) / HB_SECONDS_PER_DAY;
+   }
+#else
+   {
+      long lJulian, lMilliSec;
+      struct tm lt;
+      time_t utc;
+
+      hb_timeStampUnpackDT( dTimeStamp, &lJulian, &lMilliSec );
+      utc = ( time_t ) ( ( lJulian - HB_SYS_DATE_BASE ) * HB_SECONDS_PER_DAY + lMilliSec / 1000 );
+#if defined( HB_HAS_LOCALTIME_R )
+      localtime_r( &utc, &lt );
+#else
+      lt = *localtime( &utc );
+#endif
+      lJulian = hb_dateEncode( lt.tm_year + 1900, lt.tm_mon + 1, lt.tm_mday );
+      lMilliSec = hb_timeEncode( lt.tm_hour, lt.tm_min, lt.tm_sec, lMilliSec % 1000 );
+      dLocal = hb_timeStampPackDT( lJulian, lMilliSec );
+   }
+#endif
+
+   if( piUTCOffset )
+      *piUTCOffset = ( int ) ( ( dLocal - dTimeStamp ) * HB_SECONDS_PER_DAY +
+                               ( dLocal < dTimeStamp ? -0.5 : 0.5 ) );
+
+   return dLocal;
+}
+
 HB_MAXUINT hb_timerGet( void )
 {
    HB_TRACE( HB_TR_DEBUG, ( "hb_timerGet()" ) );

src/harbour.def

@@ -1115,6 +1115,7 @@ HB_FUN_HB_USERNAME
 HB_FUN_HB_USTUFF
 HB_FUN_HB_USUBSTR
 HB_FUN_HB_UTCOFFSET
+HB_FUN_HB_UTCTOTS
 HB_FUN_HB_UTF8ASC
 HB_FUN_HB_UTF8AT
 HB_FUN_HB_UTF8CHR
@@ -3534,6 +3535,7 @@ hb_timeStrGet
 hb_timeStrGetUTC
 hb_timeStrRawGet
 hb_timeUTCOffset
+hb_timeUTCToLocal
 hb_timeUnformat
 hb_timerGet
 hb_timerInit

src/rtl/dateshb.c

@@ -586,6 +586,7 @@ HB_FUNC( HB_WEEK )
       hb_errRT_BASE_SubstR( EG_ARG, 3012, NULL, HB_ERR_FUNCNAME, HB_ERR_ARGS_BASEPARAMS );
 }
 
+/* hb_UTCOffset( [ <tLocalTime> ] ) -> <nSeconds> */
 HB_FUNC( HB_UTCOFFSET )
 {
    if( HB_ISDATETIME( 1 ) )
@@ -599,6 +600,7 @@ HB_FUNC( HB_UTCOFFSET )
       hb_retnl( hb_timeUTCOffset() );
 }
 
+/* hb_TSToUTC( <tLocalTime> ) -> <tUTCTime> */
 HB_FUNC( HB_TSTOUTC )
 {
    if( HB_ISTIMESTAMP( 1 ) )
@@ -606,3 +608,17 @@ HB_FUNC( HB_TSTOUTC )
    else
       hb_errRT_BASE_SubstR( EG_ARG, 3012, NULL, HB_ERR_FUNCNAME, HB_ERR_ARGS_BASEPARAMS );
 }
+
+/* hb_UTCToTS( <tUTCTime> [, @<lUTCOffset> ) -> <tLocalTime> */
+HB_FUNC( HB_UTCTOTS )
+{
+   if( HB_ISTIMESTAMP( 1 ) )
+   {
+      int iUTCOffset = 0;
+
+      hb_rettd( hb_timeUTCToLocal( hb_partd( 1 ), &iUTCOffset ) );
+      hb_storni( iUTCOffset, 2 );
+   }
+   else
+      hb_errRT_BASE_SubstR( EG_ARG, 3012, NULL, HB_ERR_FUNCNAME, HB_ERR_ARGS_BASEPARAMS );
+}