3 * COPYRIGHT: See COPYING in the top level directory
4 * PROJECT: ReactOS kernel
5 * FILE: kernel/rtl/time.c
6 * PURPOSE: Conversion between Time and TimeFields
7 * PROGRAMMER: Rex Jolliff (rex@lvcablemodem.com)
10 * 08/03/98 RJJ Implemented these functions
13 /* INCLUDES *****************************************************************/
15 #include <ddk/ntddk.h>
18 #include <internal/debug.h>
20 #define TICKSPERMIN 600000000
21 #define TICKSPERSEC 10000000
22 #define TICKSPERMSEC 10000
23 #define SECSPERDAY 86400
24 #define SECSPERHOUR 3600
26 #define MINSPERHOUR 60
27 #define HOURSPERDAY 24
28 #define EPOCHWEEKDAY 1
30 #define EPOCHYEAR 1601
31 #define DAYSPERNORMALYEAR 365
32 #define DAYSPERLEAPYEAR 366
33 #define MONSPERYEAR 12
35 #define TICKSTO1970 0x019db1ded53e8000
36 #define TICKSTO1980 0x01a8e79fe1d58000
39 static const int YearLengths[2] = {DAYSPERNORMALYEAR, DAYSPERLEAPYEAR};
40 static const int MonthLengths[2][MONSPERYEAR] =
42 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
43 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
46 static __inline int IsLeapYear(int Year)
48 return Year % 4 == 0 && (Year % 100 != 0 || Year % 400 == 0) ? 1 : 0;
51 static __inline void NormalizeTimeFields(CSHORT *FieldToNormalize,
55 *FieldToNormalize = (CSHORT) (*FieldToNormalize - Modulus);
56 *CarryField = (CSHORT) (*CarryField + 1);
59 /* FUNCTIONS *****************************************************************/
64 PLARGE_INTEGER liTime,
65 PTIME_FIELDS TimeFields
69 int LeapSecondCorrections, SecondsInDay, CurYear;
70 int LeapYear, CurMonth, GMTOffset;
72 long long int Time = (long long int)liTime->QuadPart;
74 /* Extract millisecond from time and convert time into seconds */
75 TimeFields->Milliseconds = (CSHORT) ((Time % TICKSPERSEC) / TICKSPERMSEC);
76 Time = Time / TICKSPERSEC;
78 /* FIXME: Compute the number of leap second corrections here */
79 LeapSecondCorrections = 0;
81 /* FIXME: get the GMT offset here */
84 /* Split the time into days and seconds within the day */
85 Days = Time / SECSPERDAY;
86 SecondsInDay = Time % SECSPERDAY;
88 /* Adjust the values for GMT and leap seconds */
89 SecondsInDay += (GMTOffset - LeapSecondCorrections);
90 while (SecondsInDay < 0)
92 SecondsInDay += SECSPERDAY;
95 while (SecondsInDay >= SECSPERDAY)
97 SecondsInDay -= SECSPERDAY;
101 /* compute time of day */
102 TimeFields->Hour = (CSHORT) (SecondsInDay / SECSPERHOUR);
103 SecondsInDay = SecondsInDay % SECSPERHOUR;
104 TimeFields->Minute = (CSHORT) (SecondsInDay / SECSPERMIN);
105 TimeFields->Second = (CSHORT) (SecondsInDay % SECSPERMIN);
107 /* FIXME: handle the possibility that we are on a leap second (i.e. Second = 60) */
109 /* compute day of week */
110 TimeFields->Weekday = (CSHORT) ((EPOCHWEEKDAY + Days) % DAYSPERWEEK);
114 /* FIXME: handle calendar modifications */
115 CurYear += Days / DAYSPERLEAPYEAR;
116 Days -= (CurYear - EPOCHYEAR) * DAYSPERLEAPYEAR;
117 CurYear--; /* The next calculation needs CurYear - 1 */
118 Days += CurYear - CurYear / 4 + CurYear / 100 - CurYear / 400;
120 Days -= EPOCHYEAR - 1 - (EPOCHYEAR -1) / 4 + (EPOCHYEAR -1) / 100 - (EPOCHYEAR - 1) / 400;
123 LeapYear = IsLeapYear(CurYear);
124 if (Days < (long) YearLengths[LeapYear])
129 Days = Days - (long) YearLengths[LeapYear];
131 TimeFields->Year = (CSHORT) CurYear;
133 /* Compute month of year */
134 LeapYear = IsLeapYear(CurYear);
135 Months = MonthLengths[LeapYear];
136 for (CurMonth = 0; Days >= (long) Months[CurMonth]; CurMonth++)
137 Days = Days - (long) Months[CurMonth];
138 TimeFields->Month = (CSHORT) (CurMonth + 1);
139 TimeFields->Day = (CSHORT) (Days + 1);
144 RtlTimeFieldsToTime (
145 PTIME_FIELDS tfTimeFields,
150 long long int rcTime;
151 TIME_FIELDS TimeFields = *tfTimeFields;
156 /* Normalize the month value, because we don't know the length for month -1, 0, 13, 14, ... */
157 if (TimeFields.Month < 1 || TimeFields.Month > 12)
159 TimeFields.Year += (TimeFields.Month - 1) / MONSPERYEAR;
160 TimeFields.Month = ((TimeFields.Month - 1) % MONSPERYEAR) + 1;
161 if (TimeFields.Month < 1)
164 TimeFields.Month += MONSPERYEAR;
167 /* FIXME: handle calendar corrections here */
169 rcTime += (TimeFields.Year - EPOCHYEAR) * DAYSPERNORMALYEAR;
170 /* Adjust leap years */
171 rcTime += (TimeFields.Year - 1)/ 4 - (TimeFields.Year - 1) / 100 + (TimeFields.Year - 1) / 400;
172 rcTime -= EPOCHYEAR / 4 - EPOCHYEAR / 100 + EPOCHYEAR / 400;
174 /* FIXME: handle calendar corrections here */
175 Months = MonthLengths[IsLeapYear(TimeFields.Year)];
176 for (CurMonth = 1; CurMonth < TimeFields.Month; CurMonth++)
178 rcTime += Months[CurMonth - 1];
180 rcTime += TimeFields.Day - 1;
181 rcTime *= SECSPERDAY;
182 rcTime += TimeFields.Hour * SECSPERHOUR + TimeFields.Minute * SECSPERMIN +
184 rcTime *= TICKSPERSEC;
185 rcTime += TimeFields.Milliseconds * TICKSPERMSEC;
187 /* FIXME: handle UTC bias here */
188 // rcTime += UTCBias * TICKSPERMIN;
190 *Time = *(LARGE_INTEGER *)&rcTime;
198 RtlSecondsSince1970ToTime (
199 ULONG SecondsSince1970,
205 llTime = (SecondsSince1970 * TICKSPERSEC) + TICKSTO1970;
207 *Time = *(LARGE_INTEGER *)&llTime;
213 RtlSecondsSince1980ToTime (
214 ULONG SecondsSince1980,
220 llTime = (SecondsSince1980 * TICKSPERSEC) + TICKSTO1980;
222 *Time = *(LARGE_INTEGER *)&llTime;
228 RtlTimeToSecondsSince1970 (
230 PULONG SecondsSince1970
233 LARGE_INTEGER liTime;
235 liTime.QuadPart = Time->QuadPart - TICKSTO1970;
236 liTime.QuadPart = liTime.QuadPart / TICKSPERSEC;
238 if (liTime.u.HighPart != 0)
241 *SecondsSince1970 = liTime.u.LowPart;
249 RtlTimeToSecondsSince1980 (
251 PULONG SecondsSince1980
254 LARGE_INTEGER liTime;
256 liTime.QuadPart = Time->QuadPart - TICKSTO1980;
257 liTime.QuadPart = liTime.QuadPart / TICKSPERSEC;
259 if (liTime.u.HighPart != 0)
262 *SecondsSince1980 = liTime.u.LowPart;