dlls/ntdll/time.c

   1 /*
   2  * Nt time functions.
   3  *
   4  * RtlTimeToTimeFields, RtlTimeFieldsToTime and defines are taken from ReactOS and
   5  * adapted to wine with special permissions of the author. This code is
   6  * Copyright 2002 Rex Jolliff (rex@lvcablemodem.com)
   7  *
   8  * Copyright 1999 Juergen Schmied
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  */
  24
  25 #include "config.h"
  26 #include "wine/port.h"
  27
  28 #include <stdarg.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <time.h>
  32 #ifdef HAVE_SYS_TIME_H
  33 # include <sys/time.h>
  34 #endif
  35 #ifdef HAVE_UNISTD_H
  36 # include <unistd.h>
  37 #endif
  38
  39 #define NONAMELESSUNION
  40 #define NONAMELESSSTRUCT
  41 #include "windef.h"
  42 #include "winbase.h"
  43 #include "winreg.h"
  44 #include "winternl.h"
  45 #include "wine/unicode.h"
  46 #include "wine/debug.h"
  47 #include "ntdll_misc.h"
  48
  49 WINE_DEFAULT_DEBUG_CHANNEL(ntdll);
  50
  51 static CRITICAL_SECTION TIME_GetBias_section;
  52 static CRITICAL_SECTION_DEBUG critsect_debug =
  53 {
  54     0, 0, &TIME_GetBias_section,
  55     { &critsect_debug.ProcessLocksList, &critsect_debug.ProcessLocksList },
  56       0, 0, { 0, (DWORD)(__FILE__ ": TIME_GetBias_section") }
  57 };
  58 static CRITICAL_SECTION TIME_GetBias_section = { &critsect_debug, -1, 0, 0, 0, 0 };
  59
  60
  61 #define SETTIME_MAX_ADJUST 120
  62
  63 /* This structure is used to store strings that represent all of the time zones
  64  * in the world. (This is used to help GetTimeZoneInformation)
  65  */
  66 struct tagTZ_INFO
  67 {
  68     const char *psTZFromUnix;
  69     WCHAR psTZWindows[32];
  70     int bias;
  71     int dst;
  72 };
  73
  74 static const struct tagTZ_INFO TZ_INFO[] =
  75 {
  76    {"MHT",
  77     {'D','a','t','e','l','i','n','e',' ','S','t','a','n','d','a','r','d',' ',
  78      'T','i','m','e','\0'}, -720, 0},
  79    {"SST",
  80     {'S','a','m','o','a',' ','S','t','a','n','d','a','r','d',' ','T','i','m',
  81      'e','\0'}, 660, 0},
  82    {"HST",
  83     {'H','a','w','a','i','i','a','n',' ','S','t','a','n','d','a','r','d',' ',
  84      'T','i','m','e','\0'}, 600, 0},
  85    {"AKDT",
  86     {'A','l','a','s','k','a','n',' ','S','t','a','n','d','a','r','d',' ','T',
  87      'i','m','e','\0'}, 480, 1},
  88    {"PDT",
  89     {'P','a','c','i','f','i','c',' ','S','t','a','n','d','a','r','d',' ','T',
  90      'i','m','e','\0'}, 420, 1},
  91    {"MST",
  92     {'U','S',' ','M','o','u','n','t','a','i','n',' ','S','t','a','n','d','a',
  93      'r','d',' ','T','i','m','e','\0'}, 420, 0},
  94    {"MDT",
  95     {'M','o','u','n','t','a','i','n',' ','S','t','a','n','d','a','r','d',' ',
  96      'T','i','m','e','\0'}, 360, 1},
  97    {"CST",
  98     {'C','e','n','t','r','a','l',' ','A','m','e','r','i','c','a',' ','S','t',
  99      'a','n','d','a','r','d',' ','T','i','m','e','\0'}, 360, 0},
 100    {"CDT",
 101     {'C','e','n','t','r','a','l',' ','S','t','a','n','d','a','r','d',' ','T',
 102      'i','m','e','\0'}, 300, 1},
 103    {"COT",
 104     {'S','A',' ','P','a','c','i','f','i','c',' ','S','t','a','n','d','a','r',
 105      'd',' ','T','i','m','e','\0'}, 300, 0},
 106    {"EDT",
 107     {'E','a','s','t','e','r','n',' ','S','t','a','n','d','a','r','d',' ','T',
 108      'i','m','e','\0'}, 240, 1},
 109    {"EST",
 110     {'U','S',' ','E','a','s','t','e','r','n',' ','S','t','a','n','d','a','r',
 111      'd',' ','T','i','m','e','\0'}, 300, 0},
 112    {"ADT",
 113     {'A','t','l','a','n','t','i','c',' ','S','t','a','n','d','a','r','d',' ',
 114      'T','i','m','e','\0'}, 180, 1},
 115    {"VET",
 116     {'S','A',' ','W','e','s','t','e','r','n',' ','S','t','a','n','d','a','r',
 117      'd',' ','T','i','m','e','\0'}, 240, 0},
 118    {"CLT",
 119     {'P','a','c','i','f','i','c',' ','S','A',' ','S','t','a','n','d','a','r',
 120      'd',' ','T','i','m','e','\0'}, 240, 0},
 121    {"NDT",
 122     {'N','e','w','f','o','u','n','d','l','a','n','d',' ','S','t','a','n','d',
 123      'a','r','d',' ','T','i','m','e','\0'}, 150, 1},
 124    {"BRT",
 125     {'E','.',' ','S','o','u','t','h',' ','A','m','e','r','i','c','a',' ','S',
 126      't','a','n','d','a','r','d',' ','T','i','m','e','\0'}, 180, 0},
 127    {"ART",
 128     {'S','A',' ','E','a','s','t','e','r','n',' ','S','t','a','n','d','a','r',
 129      'd',' ','T','i','m','e','\0'}, 180, 0},
 130    {"WGST",
 131     {'G','r','e','e','n','l','a','n','d',' ','S','t','a','n','d','a','r','d',
 132      ' ','T','i','m','e','\0'}, 120, 1},
 133    {"GST",
 134     {'M','i','d','-','A','t','l','a','n','t','i','c',' ','S','t','a','n','d',
 135      'a','r','d',' ','T','i','m','e','\0'}, 120, 0},
 136    {"AZOST",
 137     {'A','z','o','r','e','s',' ','S','t','a','n','d','a','r','d',' ','T','i',
 138      'm','e','\0'}, 0, 1},
 139    {"CVT",
 140     {'C','a','p','e',' ','V','e','r','d','e',' ','S','t','a','n','d','a','r',
 141      'd',' ','T','i','m','e','\0'}, 60, 0},
 142    {"WET",
 143     {'G','r','e','e','n','w','i','c','h',' ','S','t','a','n','d','a','r','d',
 144      ' ','T','i','m','e','\0'}, 0, 0},
 145    {"BST",
 146     {'G','M','T',' ','S','t','a','n','d','a','r','d',' ','T','i','m','e','\0'},
 147     -60, 1},
 148    {"GMT",
 149     {'G','M','T',' ','S','t','a','n','d','a','r','d',' ','T','i','m','e','\0'},
 150     0, 0},
 151    {"CEST",
 152     {'C','e','n','t','r','a','l',' ','E','u','r','o','p','e',' ','S','t','a',
 153      'n','d','a','r','d',' ','T','i','m','e','\0'}, -120, 1},
 154    {"WAT",
 155     {'W','.',' ','C','e','n','t','r','a','l',' ','A','f','r','i','c','a',' ',
 156      'S','t','a','n','d','a','r','d',' ','T','i','m','e','\0'}, -60, 0},
 157    {"EEST",
 158     {'E','.',' ','E','u','r','o','p','e',' ','S','t','a','n','d','a','r','d',
 159      ' ','T','i','m','e','\0'}, -180, 1},
 160    {"EET",
 161     {'E','g','y','p','t',' ','S','t','a','n','d','a','r','d',' ','T','i','m',
 162      'e','\0'}, -120, 0},
 163    {"CAT",
 164     {'S','o','u','t','h',' ','A','f','r','i','c','a',' ','S','t','a','n','d',
 165      'a','r','d',' ','T','i','m','e','\0'}, -120, 0},
 166    {"IST",
 167     {'I','s','r','a','e','l',' ','S','t','a','n','d','a','r','d',' ','T','i',
 168      'm','e','\0'}, -120, 0},
 169    {"ADT",
 170     {'A','r','a','b','i','c',' ','S','t','a','n','d','a','r','d',' ','T','i',
 171      'm','e','\0'}, -240, 1},
 172    {"AST",
 173     {'A','r','a','b',' ','S','t','a','n','d','a','r','d',' ','T','i','m','e',
 174      '\0'}, -180, 0},
 175    {"MSD",
 176     {'R','u','s','s','i','a','n',' ','S','t','a','n','d','a','r','d',' ','T',
 177      'i','m','e','\0'}, -240, 1},
 178    {"EAT",
 179     {'E','.',' ','A','f','r','i','c','a',' ','S','t','a','n','d','a','r','d',
 180      ' ','T','i','m','e','\0'}, -180, 0},
 181    {"IRST",
 182     {'I','r','a','n',' ','S','t','a','n','d','a','r','d',' ','T','i','m','e',
 183      '\0'}, -270, 1},
 184    {"GST",
 185     {'A','r','a','b','i','a','n',' ','S','t','a','n','d','a','r','d',' ','T',
 186      'i','m','e','\0'}, -240, 0},
 187    {"AZST",
 188     {'C','a','u','c','a','s','u','s',' ','S','t','a','n','d','a','r','d',' ',
 189      'T','i','m','e','\0'}, -300, 1},
 190    {"AFT",
 191     {'A','f','g','h','a','n','i','s','t','a','n',' ','S','t','a','n','d','a',
 192      'r','d',' ','T','i','m','e','\0'}, -270, 0},
 193    {"YEKST",
 194     {'E','k','a','t','e','r','i','n','b','u','r','g',' ','S','t','a','n','d',
 195      'a','r','d',' ','T','i','m','e','\0'}, -360, 1},
 196    {"PKT",
 197     {'W','e','s','t',' ','A','s','i','a',' ','S','t','a','n','d','a','r','d',
 198      ' ','T','i','m','e','\0'}, -300, 0},
 199    {"IST",
 200     {'I','n','d','i','a',' ','S','t','a','n','d','a','r','d',' ','T','i','m',
 201      'e','\0'}, -330, 0},
 202    {"NPT",
 203     {'N','e','p','a','l',' ','S','t','a','n','d','a','r','d',' ','T','i','m',
 204      'e','\0'}, -345, 0},
 205    {"ALMST",
 206     {'N','.',' ','C','e','n','t','r','a','l',' ','A','s','i','a',' ','S','t',
 207      'a','n','d','a','r','d',' ','T','i','m','e','\0'}, -420, 1},
 208    {"BDT",
 209     {'C','e','n','t','r','a','l',' ','A','s','i','a',' ','S','t','a','n','d',
 210      'a','r','d',' ','T','i','m','e','\0'}, -360, 0},
 211    {"LKT",
 212     {'S','r','i',' ','L','a','n','k','a',' ','S','t','a','n','d','a','r','d',
 213      ' ','T','i','m','e','\0'}, -360, 0},
 214    {"MMT",
 215     {'M','y','a','n','m','a','r',' ','S','t','a','n','d','a','r','d',' ','T',
 216      'i','m','e','\0'}, -390, 0},
 217    {"ICT",
 218     {'S','E',' ','A','s','i','a',' ','S','t','a','n','d','a','r','d',' ','T',
 219      'i','m','e','\0'}, -420, 0},
 220    {"KRAST",
 221     {'N','o','r','t','h',' ','A','s','i','a',' ','S','t','a','n','d','a','r',
 222      'd',' ','T','i','m','e','\0'}, -480, 1},
 223    {"CST",
 224     {'C','h','i','n','a',' ','S','t','a','n','d','a','r','d',' ','T','i','m',
 225      'e','\0'}, -480, 0},
 226    {"IRKST",
 227     {'N','o','r','t','h',' ','A','s','i','a',' ','E','a','s','t',' ','S','t',
 228      'a','n','d','a','r','d',' ','T','i','m','e','\0'}, -540, 1},
 229    {"SGT",
 230     {'M','a','l','a','y',' ','P','e','n','i','n','s','u','l','a',' ','S','t',
 231      'a','n','d','a','r','d',' ','T','i','m','e','\0'}, -480, 0},
 232    {"WST",
 233     {'W','.',' ','A','u','s','t','r','a','l','i','a',' ','S','t','a','n','d',
 234      'a','r','d',' ','T','i','m','e','\0'}, -480, 0},
 235    {"JST",
 236     {'T','o','k','y','o',' ','S','t','a','n','d','a','r','d',' ','T','i','m',
 237      'e','\0'}, -540, 0},
 238    {"KST",
 239     {'K','o','r','e','a',' ','S','t','a','n','d','a','r','d',' ','T','i','m',
 240      'e','\0'}, -540, 0},
 241    {"YAKST",
 242     {'Y','a','k','u','t','s','k',' ','S','t','a','n','d','a','r','d',' ','T',
 243      'i','m','e','\0'}, -600, 1},
 244    {"CST",
 245     {'C','e','n','.',' ','A','u','s','t','r','a','l','i','a',' ','S','t','a',
 246      'n','d','a','r','d',' ','T','i','m','e','\0'}, -570, 0},
 247    {"EST",
 248     {'E','.',' ','A','u','s','t','r','a','l','i','a',' ','S','t','a','n','d',
 249      'a','r','d',' ','T','i','m','e','\0'}, -600, 0},
 250    {"GST",
 251     {'W','e','s','t',' ','P','a','c','i','f','i','c',' ','S','t','a','n','d',
 252      'a','r','d',' ','T','i','m','e','\0'}, -600, 0},
 253    {"VLAST",
 254     {'V','l','a','d','i','v','o','s','t','o','k',' ','S','t','a','n','d','a',
 255      'r','d',' ','T','i','m','e','\0'}, -660, 1},
 256    {"MAGST",
 257     {'C','e','n','t','r','a','l',' ','P','a','c','i','f','i','c',' ','S','t',
 258      'a','n','d','a','r','d',' ','T','i','m','e','\0'}, -720, 1},
 259    {"NZST",
 260     {'N','e','w',' ','Z','e','a','l','a','n','d',' ','S','t','a','n','d','a',
 261      'r','d',' ','T','i','m','e','\0'}, -720, 0},
 262    {"FJT",
 263     {'F','i','j','i',' ','S','t','a','n','d','a','r','d',' ','T','i','m','e',
 264      '\0'}, -720, 0},
 265    {"TOT",
 266     {'T','o','n','g','a',' ','S','t','a','n','d','a','r','d',' ','T','i','m',
 267      'e','\0'}, -780, 0}
 268 };
 269
 270 #define TICKSPERSEC        10000000
 271 #define TICKSPERMSEC       10000
 272 #define SECSPERDAY         86400
 273 #define SECSPERHOUR        3600
 274 #define SECSPERMIN         60
 275 #define MINSPERHOUR        60
 276 #define HOURSPERDAY        24
 277 #define EPOCHWEEKDAY       1  /* Jan 1, 1601 was Monday */
 278 #define DAYSPERWEEK        7
 279 #define EPOCHYEAR          1601
 280 #define DAYSPERNORMALYEAR  365
 281 #define DAYSPERLEAPYEAR    366
 282 #define MONSPERYEAR        12
 283 #define DAYSPERQUADRICENTENNIUM (365 * 400 + 97)
 284 #define DAYSPERNORMALCENTURY (365 * 100 + 24)
 285 #define DAYSPERNORMALQUADRENNIUM (365 * 4 + 1)
 286
 287 /* 1601 to 1970 is 369 years plus 89 leap days */
 288 #define SECS_1601_TO_1970  ((369 * 365 + 89) * (ULONGLONG)SECSPERDAY)
 289 #define TICKS_1601_TO_1970 (SECS_1601_TO_1970 * TICKSPERSEC)
 290 /* 1601 to 1980 is 379 years plus 91 leap days */
 291 #define SECS_1601_TO_1980  ((379 * 365 + 91) * (ULONGLONG)SECSPERDAY)
 292 #define TICKS_1601_TO_1980 (SECS_1601_TO_1980 * TICKSPERSEC)
 293
 294
 295 static const int MonthLengths[2][MONSPERYEAR] =
 296 {
 297         { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
 298         { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 299 };
 300
 301 static const int YearDays[2][MONSPERYEAR+1] =
 302 {
 303         { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
 304         { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
 305 };
 306
 307 static inline int IsLeapYear(int Year)
 308 {
 309         return Year % 4 == 0 && (Year % 100 != 0 || Year % 400 == 0) ? 1 : 0;
 310 }
 311
 312 static inline void NormalizeTimeFields(CSHORT *FieldToNormalize, CSHORT *CarryField,int Modulus)
 313 {
 314         *FieldToNormalize = (CSHORT) (*FieldToNormalize - Modulus);
 315         *CarryField = (CSHORT) (*CarryField + 1);
 316 }
 317
 318 /***********************************************************************
 319  *              NTDLL_get_server_timeout
 320  *
 321  * Convert a NTDLL timeout into a timeval struct to send to the server.
 322  */
 323 void NTDLL_get_server_timeout( abs_time_t *when, const LARGE_INTEGER *timeout )
 324 {
 325     UINT remainder;
 326
 327     if (!timeout)  /* infinite timeout */
 328     {
 329         when->sec = when->usec = 0;
 330     }
 331     else if (timeout->QuadPart <= 0)  /* relative timeout */
 332     {
 333         struct timeval tv;
 334         ULONG sec = RtlEnlargedUnsignedDivide( -timeout->QuadPart, TICKSPERSEC, &remainder );
 335         gettimeofday( &tv, 0 );
 336         when->sec = tv.tv_sec + sec;
 337         if ((when->usec = tv.tv_usec + (remainder / 10)) >= 1000000)
 338         {
 339             when->usec -= 1000000;
 340             when->sec++;
 341         }
 342     }
 343     else  /* absolute time */
 344     {
 345         when->sec = RtlEnlargedUnsignedDivide( timeout->QuadPart - TICKS_1601_TO_1970,
 346                                                   TICKSPERSEC, &remainder );
 347         when->usec = remainder / 10;
 348     }
 349 }
 350
 351
 352 /******************************************************************************
 353  *       RtlTimeToTimeFields [NTDLL.@]
 354  *
 355  * Convert a time into a TIME_FIELDS structure.
 356  *
 357  * PARAMS
 358  *   liTime     [I] Time to convert.
 359  *   TimeFields [O] Destination for the converted time.
 360  *
 361  * RETURNS
 362  *   Nothing.
 363  */
 364 VOID WINAPI RtlTimeToTimeFields(
 365         const LARGE_INTEGER *liTime,
 366         PTIME_FIELDS TimeFields)
 367 {
 368         int SecondsInDay, DeltaYear;
 369         int LeapYear, CurMonth;
 370         long int Days;
 371         LONGLONG Time = liTime->QuadPart;
 372
 373         /* Extract millisecond from time and convert time into seconds */
 374         TimeFields->Milliseconds = (CSHORT) ((Time % TICKSPERSEC) / TICKSPERMSEC);
 375         Time = Time / TICKSPERSEC;
 376
 377         /* The native version of RtlTimeToTimeFields does not take leap seconds
 378          * into account */
 379
 380         /* Split the time into days and seconds within the day */
 381         Days = Time / SECSPERDAY;
 382         SecondsInDay = Time % SECSPERDAY;
 383
 384         /* compute time of day */
 385         TimeFields->Hour = (CSHORT) (SecondsInDay / SECSPERHOUR);
 386         SecondsInDay = SecondsInDay % SECSPERHOUR;
 387         TimeFields->Minute = (CSHORT) (SecondsInDay / SECSPERMIN);
 388         TimeFields->Second = (CSHORT) (SecondsInDay % SECSPERMIN);
 389
 390         /* compute day of week */
 391         TimeFields->Weekday = (CSHORT) ((EPOCHWEEKDAY + Days) % DAYSPERWEEK);
 392
 393         /* compute year */
 394         /* FIXME: handle calendar modifications */
 395         TimeFields->Year = EPOCHYEAR;
 396         DeltaYear = Days / DAYSPERQUADRICENTENNIUM;
 397         TimeFields->Year += DeltaYear * 400;
 398         Days -= DeltaYear * DAYSPERQUADRICENTENNIUM;
 399         DeltaYear = Days / DAYSPERNORMALCENTURY;
 400         TimeFields->Year += DeltaYear * 100;
 401         Days -= DeltaYear * DAYSPERNORMALCENTURY;
 402         DeltaYear = Days / DAYSPERNORMALQUADRENNIUM;
 403         TimeFields->Year += DeltaYear * 4;
 404         Days -= DeltaYear * DAYSPERNORMALQUADRENNIUM;
 405         DeltaYear = Days / DAYSPERNORMALYEAR;
 406         TimeFields->Year += DeltaYear;
 407         Days -= DeltaYear * DAYSPERNORMALYEAR;
 408
 409         LeapYear = IsLeapYear(TimeFields->Year);
 410
 411         /* Compute month of year */
 412         CurMonth = 1;
 413         while (Days >= YearDays[LeapYear][CurMonth]) CurMonth++;
 414         TimeFields->Day = Days - YearDays[LeapYear][CurMonth-1] + 1;
 415         TimeFields->Month = CurMonth;
 416 }
 417
 418 /******************************************************************************
 419  *       RtlTimeFieldsToTime [NTDLL.@]
 420  *
 421  * Convert a TIME_FIELDS structure into a time.
 422  *
 423  * PARAMS
 424  *   ftTimeFields [I] TIME_FIELDS structure to convert.
 425  *   Time         [O] Destination for the converted time.
 426  *
 427  * RETURNS
 428  *   Success: TRUE.
 429  *   Failure: FALSE.
 430  */
 431 BOOLEAN WINAPI RtlTimeFieldsToTime(
 432         PTIME_FIELDS tfTimeFields,
 433         PLARGE_INTEGER Time)
 434 {
 435         int CurYear, DeltaYear;
 436         LONGLONG rcTime;
 437         TIME_FIELDS TimeFields = *tfTimeFields;
 438
 439         rcTime = 0;
 440
 441         /* FIXME: normalize the TIME_FIELDS structure here */
 442         while (TimeFields.Second >= SECSPERMIN)
 443         { NormalizeTimeFields(&TimeFields.Second, &TimeFields.Minute, SECSPERMIN);
 444         }
 445         while (TimeFields.Minute >= MINSPERHOUR)
 446         { NormalizeTimeFields(&TimeFields.Minute, &TimeFields.Hour, MINSPERHOUR);
 447         }
 448         while (TimeFields.Hour >= HOURSPERDAY)
 449         { NormalizeTimeFields(&TimeFields.Hour, &TimeFields.Day, HOURSPERDAY);
 450         }
 451         while (TimeFields.Day > MonthLengths[IsLeapYear(TimeFields.Year)][TimeFields.Month - 1])
 452         { NormalizeTimeFields(&TimeFields.Day, &TimeFields.Month,
 453                               MonthLengths[IsLeapYear(TimeFields.Year)][TimeFields.Month - 1]);
 454         }
 455         while (TimeFields.Month > MONSPERYEAR)
 456         { NormalizeTimeFields(&TimeFields.Month, &TimeFields.Year, MONSPERYEAR);
 457         }
 458
 459         /* FIXME: handle calendar corrections here */
 460         CurYear = TimeFields.Year - EPOCHYEAR;
 461         DeltaYear = CurYear / 400;
 462         CurYear -= DeltaYear * 400;
 463         rcTime += DeltaYear * DAYSPERQUADRICENTENNIUM;
 464         DeltaYear = CurYear / 100;
 465         CurYear -= DeltaYear * 100;
 466         rcTime += DeltaYear * DAYSPERNORMALCENTURY;
 467         DeltaYear = CurYear / 4;
 468         CurYear -= DeltaYear * 4;
 469         rcTime += DeltaYear * DAYSPERNORMALQUADRENNIUM;
 470         rcTime += CurYear * DAYSPERNORMALYEAR;
 471         rcTime += YearDays[IsLeapYear(TimeFields.Year)][TimeFields.Month - 1];
 472         rcTime += TimeFields.Day - 1;
 473         rcTime *= SECSPERDAY;
 474         rcTime += TimeFields.Hour * SECSPERHOUR + TimeFields.Minute * SECSPERMIN + TimeFields.Second;
 475         rcTime *= TICKSPERSEC;
 476         rcTime += TimeFields.Milliseconds * TICKSPERMSEC;
 477         Time->QuadPart = rcTime;
 478
 479         return TRUE;
 480 }
 481
 482 /***********************************************************************
 483  *       TIME_GetBias [internal]
 484  *
 485  * Helper function calculates delta local time from UTC.
 486  *
 487  * PARAMS
 488  *   utc [I] The current utc time.
 489  *   pdaylight [I] Local daylight.
 490  *
 491  * RETURNS
 492  *   The bias for the current timezone.
 493  */
 494 static int TIME_GetBias(time_t utc, int *pdaylight)
 495 {
 496     struct tm *ptm;
 497     static time_t last_utc;
 498     static int last_bias;
 499     static int last_daylight;
 500     int ret;
 501
 502     RtlEnterCriticalSection( &TIME_GetBias_section );
 503     if(utc == last_utc)
 504     {
 505         *pdaylight = last_daylight;
 506         ret = last_bias;
 507     } else
 508     {
 509         ptm = localtime(&utc);
 510         *pdaylight = last_daylight =
 511             ptm->tm_isdst; /* daylight for local timezone */
 512         ptm = gmtime(&utc);
 513         ptm->tm_isdst = *pdaylight; /* use local daylight, not that of Greenwich */
 514         last_utc = utc;
 515         ret = last_bias = (int)(utc-mktime(ptm));
 516     }
 517     RtlLeaveCriticalSection( &TIME_GetBias_section );
 518     return ret;
 519 }
 520
 521 /******************************************************************************
 522  *        RtlLocalTimeToSystemTime [NTDLL.@]
 523  *
 524  * Convert a local time into system time.
 525  *
 526  * PARAMS
 527  *   LocalTime  [I] Local time to convert.
 528  *   SystemTime [O] Destination for the converted time.
 529  *
 530  * RETURNS
 531  *   Success: STATUS_SUCCESS.
 532  *   Failure: An NTSTATUS error code indicating the problem.
 533  */
 534 NTSTATUS WINAPI RtlLocalTimeToSystemTime( const LARGE_INTEGER *LocalTime,
 535                                           PLARGE_INTEGER SystemTime)
 536 {
 537     time_t gmt;
 538     int bias, daylight;
 539
 540     TRACE("(%p, %p)\n", LocalTime, SystemTime);
 541
 542     gmt = time(NULL);
 543     bias = TIME_GetBias(gmt, &daylight);
 544
 545     SystemTime->QuadPart = LocalTime->QuadPart - bias * (LONGLONG)10000000;
 546     return STATUS_SUCCESS;
 547 }
 548
 549 /******************************************************************************
 550  *       RtlSystemTimeToLocalTime [NTDLL.@]
 551  *
 552  * Convert a system time into a local time.
 553  *
 554  * PARAMS
 555  *   SystemTime [I] System time to convert.
 556  *   LocalTime  [O] Destination for the converted time.
 557  *
 558  * RETURNS
 559  *   Success: STATUS_SUCCESS.
 560  *   Failure: An NTSTATUS error code indicating the problem.
 561  */
 562 NTSTATUS WINAPI RtlSystemTimeToLocalTime( const LARGE_INTEGER *SystemTime,
 563                                           PLARGE_INTEGER LocalTime )
 564 {
 565     time_t gmt;
 566     int bias, daylight;
 567
 568     TRACE("(%p, %p)\n", SystemTime, LocalTime);
 569
 570     gmt = time(NULL);
 571     bias = TIME_GetBias(gmt, &daylight);
 572
 573     LocalTime->QuadPart = SystemTime->QuadPart + bias * (LONGLONG)10000000;
 574     return STATUS_SUCCESS;
 575 }
 576
 577 /******************************************************************************
 578  *       RtlTimeToSecondsSince1970 [NTDLL.@]
 579  *
 580  * Convert a time into a count of seconds since 1970.
 581  *
 582  * PARAMS
 583  *   Time    [I] Time to convert.
 584  *   Seconds [O] Destination for the converted time.
 585  *
 586  * RETURNS
 587  *   Success: TRUE.
 588  *   Failure: FALSE, if the resulting value will not fit in a DWORD.
 589  */
 590 BOOLEAN WINAPI RtlTimeToSecondsSince1970( const LARGE_INTEGER *Time, LPDWORD Seconds )
 591 {
 592     ULONGLONG tmp = ((ULONGLONG)Time->u.HighPart << 32) | Time->u.LowPart;
 593     tmp = RtlLargeIntegerDivide( tmp, 10000000, NULL );
 594     tmp -= SECS_1601_TO_1970;
 595     if (tmp > 0xffffffff) return FALSE;
 596     *Seconds = (DWORD)tmp;
 597     return TRUE;
 598 }
 599
 600 /******************************************************************************
 601  *       RtlTimeToSecondsSince1980 [NTDLL.@]
 602  *
 603  * Convert a time into a count of seconds since 1980.
 604  *
 605  * PARAMS
 606  *   Time    [I] Time to convert.
 607  *   Seconds [O] Destination for the converted time.
 608  *
 609  * RETURNS
 610  *   Success: TRUE.
 611  *   Failure: FALSE, if the resulting value will not fit in a DWORD.
 612  */
 613 BOOLEAN WINAPI RtlTimeToSecondsSince1980( const LARGE_INTEGER *Time, LPDWORD Seconds )
 614 {
 615     ULONGLONG tmp = ((ULONGLONG)Time->u.HighPart << 32) | Time->u.LowPart;
 616     tmp = RtlLargeIntegerDivide( tmp, 10000000, NULL );
 617     tmp -= SECS_1601_TO_1980;
 618     if (tmp > 0xffffffff) return FALSE;
 619     *Seconds = (DWORD)tmp;
 620     return TRUE;
 621 }
 622
 623 /******************************************************************************
 624  *       RtlSecondsSince1970ToTime [NTDLL.@]
 625  *
 626  * Convert a count of seconds since 1970 to a time.
 627  *
 628  * PARAMS
 629  *   Seconds [I] Time to convert.
 630  *   Time    [O] Destination for the converted time.
 631  *
 632  * RETURNS
 633  *   Nothing.
 634  */
 635 void WINAPI RtlSecondsSince1970ToTime( DWORD Seconds, LARGE_INTEGER *Time )
 636 {
 637     ULONGLONG secs = Seconds * (ULONGLONG)TICKSPERSEC + TICKS_1601_TO_1970;
 638     Time->u.LowPart  = (DWORD)secs;
 639     Time->u.HighPart = (DWORD)(secs >> 32);
 640 }
 641
 642 /******************************************************************************
 643  *       RtlSecondsSince1980ToTime [NTDLL.@]
 644  *
 645  * Convert a count of seconds since 1980 to a time.
 646  *
 647  * PARAMS
 648  *   Seconds [I] Time to convert.
 649  *   Time    [O] Destination for the converted time.
 650  *
 651  * RETURNS
 652  *   Nothing.
 653  */
 654 void WINAPI RtlSecondsSince1980ToTime( DWORD Seconds, LARGE_INTEGER *Time )
 655 {
 656     ULONGLONG secs = Seconds * (ULONGLONG)TICKSPERSEC + TICKS_1601_TO_1980;
 657     Time->u.LowPart  = (DWORD)secs;
 658     Time->u.HighPart = (DWORD)(secs >> 32);
 659 }
 660
 661 /******************************************************************************
 662  *       RtlTimeToElapsedTimeFields [NTDLL.@]
 663  *
 664  * Convert a time to a count of elapsed seconds.
 665  *
 666  * PARAMS
 667  *   Time       [I] Time to convert.
 668  *   TimeFields [O] Destination for the converted time.
 669  *
 670  * RETURNS
 671  *   Nothing.
 672  */
 673 void WINAPI RtlTimeToElapsedTimeFields( const LARGE_INTEGER *Time, PTIME_FIELDS TimeFields )
 674 {
 675     LONGLONG time;
 676     UINT rem;
 677
 678     time = RtlExtendedLargeIntegerDivide( Time->QuadPart, TICKSPERSEC, &rem );
 679     TimeFields->Milliseconds = rem / TICKSPERMSEC;
 680
 681     /* time is now in seconds */
 682     TimeFields->Year  = 0;
 683     TimeFields->Month = 0;
 684     TimeFields->Day   = RtlExtendedLargeIntegerDivide( time, SECSPERDAY, &rem );
 685
 686     /* rem is now the remaining seconds in the last day */
 687     TimeFields->Second = rem % 60;
 688     rem /= 60;
 689     TimeFields->Minute = rem % 60;
 690     TimeFields->Hour = rem / 60;
 691 }
 692
 693 /***********************************************************************
 694  *       NtQuerySystemTime [NTDLL.@]
 695  *       ZwQuerySystemTime [NTDLL.@]
 696  *
 697  * Get the current system time.
 698  *
 699  * PARAMS
 700  *   Time [O] Destination for the current system time.
 701  *
 702  * RETURNS
 703  *   Success: STATUS_SUCCESS.
 704  *   Failure: An NTSTATUS error code indicating the problem.
 705  */
 706 NTSTATUS WINAPI NtQuerySystemTime( PLARGE_INTEGER Time )
 707 {
 708     struct timeval now;
 709
 710     gettimeofday( &now, 0 );
 711     Time->QuadPart = now.tv_sec * (ULONGLONG)TICKSPERSEC + TICKS_1601_TO_1970;
 712     Time->QuadPart += now.tv_usec * 10;
 713     return STATUS_SUCCESS;
 714 }
 715
 716 /***********************************************************************
 717  *        TIME_GetTZAsStr [internal]
 718  *
 719  * Helper function that returns the given timezone as a string.
 720  *
 721  * PARAMS
 722  *   utc [I] The current utc time.
 723  *   bias [I] The bias of the current timezone.
 724  *   dst [I] ??
 725  *
 726  * RETURNS
 727  *   Timezone name.
 728  *
 729  * NOTES:
 730  *   This could be done with a hash table instead of merely iterating through a
 731  *   table, however with the small amount of entries (60 or so) I didn't think
 732  *   it was worth it.
 733  */
 734 static const WCHAR* TIME_GetTZAsStr (time_t utc, int bias, int dst)
 735 {
 736    char psTZName[7];
 737    struct tm *ptm = localtime(&utc);
 738    int i;
 739
 740    if (!strftime (psTZName, 7, "%Z", ptm))
 741       return (NULL);
 742
 743    for (i=0; i<(sizeof(TZ_INFO) / sizeof(struct tagTZ_INFO)); i++)
 744    {
 745       if ( strcmp(TZ_INFO[i].psTZFromUnix, psTZName) == 0 &&
 746            TZ_INFO[i].bias == bias &&
 747            TZ_INFO[i].dst == dst
 748          )
 749             return TZ_INFO[i].psTZWindows;
 750    }
 751
 752    return NULL;
 753 }
 754
 755 /***********************************************************************
 756  *      RtlQueryTimeZoneInformation [NTDLL.@]
 757  *
 758  * Get information about the current timezone.
 759  *
 760  * PARAMS
 761  *   tzinfo [O] Destination for the retrieved timezone info.
 762  *
 763  * RETURNS
 764  *   Success: STATUS_SUCCESS.
 765  *   Failure: An NTSTATUS error code indicating the problem.
 766  */
 767 NTSTATUS WINAPI RtlQueryTimeZoneInformation(LPTIME_ZONE_INFORMATION tzinfo)
 768 {
 769     time_t gmt;
 770     int bias, daylight;
 771     const WCHAR *psTZ;
 772
 773     memset(tzinfo, 0, sizeof(TIME_ZONE_INFORMATION));
 774
 775     gmt = time(NULL);
 776     bias = TIME_GetBias(gmt, &daylight);
 777
 778     tzinfo->Bias = -bias / 60;
 779     tzinfo->StandardBias = 0;
 780     tzinfo->DaylightBias = -60;
 781     psTZ = TIME_GetTZAsStr (gmt, (-bias/60), daylight);
 782     if (psTZ) strcpyW( tzinfo->StandardName, psTZ );
 783     return STATUS_SUCCESS;
 784 }
 785
 786 /***********************************************************************
 787  *       RtlSetTimeZoneInformation [NTDLL.@]
 788  *
 789  * Set the current time zone information.
 790  *
 791  * PARAMS
 792  *   tzinfo [I] Timezone information to set.
 793  *
 794  * RETURNS
 795  *   Success: STATUS_SUCCESS.
 796  *   Failure: An NTSTATUS error code indicating the problem.
 797  *
 798  * BUGS
 799  *   Uses the obsolete unix timezone structure and tz_dsttime member.
 800  */
 801 NTSTATUS WINAPI RtlSetTimeZoneInformation( const TIME_ZONE_INFORMATION *tzinfo )
 802 {
 803 #ifdef HAVE_SETTIMEOFDAY
 804     struct timezone tz;
 805
 806     tz.tz_minuteswest = tzinfo->Bias;
 807 #ifdef DST_NONE
 808     tz.tz_dsttime = DST_NONE;
 809 #else
 810     tz.tz_dsttime = 0;
 811 #endif
 812     if(!settimeofday(NULL, &tz))
 813         return STATUS_SUCCESS;
 814 #endif
 815     return STATUS_PRIVILEGE_NOT_HELD;
 816 }
 817
 818 /***********************************************************************
 819  *        NtSetSystemTime [NTDLL.@]
 820  *        ZwSetSystemTime [NTDLL.@]
 821  *
 822  * Set the system time.
 823  *
 824  * PARAMS
 825  *   NewTime [I] The time to set.
 826  *   OldTime [O] Optional destination for the previous system time.
 827  *
 828  * RETURNS
 829  *   Success: STATUS_SUCCESS.
 830  *   Failure: An NTSTATUS error code indicating the problem.
 831  */
 832 NTSTATUS WINAPI NtSetSystemTime(const LARGE_INTEGER *NewTime, LARGE_INTEGER *OldTime)
 833 {
 834     TIME_FIELDS tf;
 835     struct timeval tv;
 836     struct timezone tz;
 837     struct tm t;
 838     time_t sec, oldsec;
 839     int dst, bias;
 840     int err;
 841
 842     /* Return the old time if necessary */
 843     if(OldTime)
 844         NtQuerySystemTime(OldTime);
 845
 846     RtlTimeToTimeFields(NewTime, &tf);
 847
 848     /* call gettimeofday to get the current timezone */
 849     gettimeofday(&tv, &tz);
 850     oldsec = tv.tv_sec;
 851     /* get delta local time from utc */
 852     bias = TIME_GetBias(oldsec, &dst);
 853
 854     /* get the number of seconds */
 855     t.tm_sec = tf.Second;
 856     t.tm_min = tf.Minute;
 857     t.tm_hour = tf.Hour;
 858     t.tm_mday = tf.Day;
 859     t.tm_mon = tf.Month - 1;
 860     t.tm_year = tf.Year - 1900;
 861     t.tm_isdst = dst;
 862     sec = mktime (&t);
 863     /* correct for timezone and daylight */
 864     sec += bias;
 865
 866     /* set the new time */
 867     tv.tv_sec = sec;
 868     tv.tv_usec = tf.Milliseconds * 1000;
 869
 870     /* error and sanity check*/
 871     if(sec == (time_t)-1 || abs((int)(sec-oldsec)) > SETTIME_MAX_ADJUST) {
 872         err = 2;
 873     } else {
 874 #ifdef HAVE_SETTIMEOFDAY
 875         err = settimeofday(&tv, NULL); /* 0 is OK, -1 is error */
 876         if(err == 0)
 877             return STATUS_SUCCESS;
 878 #else
 879         err = 1;
 880 #endif
 881     }
 882
 883     ERR("Cannot set time to %d/%d/%d %d:%d:%d Time adjustment %ld %s\n",
 884             tf.Year, tf.Month, tf.Day, tf.Hour, tf.Minute, tf.Second,
 885             (long)(sec-oldsec),
 886             err == -1 ? "No Permission"
 887                       : sec == (time_t)-1 ? "" : "is too large." );
 888
 889     if(err == 2)
 890         return STATUS_INVALID_PARAMETER;
 891     else if(err == -1)
 892         return STATUS_PRIVILEGE_NOT_HELD;
 893     else
 894         return STATUS_NOT_IMPLEMENTED;
 895 }