1 /*-------------------------------------------------------------------------
4 * Definitions for the date/time and other date/time support code.
5 * The support code is shared with other date data types,
6 * including abstime, reltime, date, and time.
9 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
10 * Portions Copyright (c) 1994, Regents of the University of California
12 * $PostgreSQL: pgsql/src/include/utils/datetime.h,v 1.61 2006/09/16 20:14:33 tgl Exp $
14 *-------------------------------------------------------------------------
22 #include "utils/timestamp.h"
23 #include "utils/tzparser.h"
26 /* ----------------------------------------------------------------
27 * time types + support macros
29 * String definitions for standard time quantities.
31 * These strings are the defaults used to form output time strings.
32 * Other alternate forms are hardcoded into token tables in datetime.c.
33 * ----------------------------------------------------------------
37 #define DCURRENT "current"
39 #define INVALID "invalid"
40 #define EARLY "-infinity"
41 #define LATE "infinity"
44 #define TOMORROW "tomorrow"
45 #define YESTERDAY "yesterday"
48 #define DMICROSEC "usecond"
49 #define DMILLISEC "msecond"
50 #define DSECOND "second"
51 #define DMINUTE "minute"
55 #define DMONTH "month"
56 #define DQUARTER "quarter"
58 #define DDECADE "decade"
59 #define DCENTURY "century"
60 #define DMILLENNIUM "millennium"
63 #define DTIMEZONE "timezone"
66 * Fundamental time field definitions for parsing.
68 * Meridian: am, pm, or 24-hour style.
80 * Fields for time decoding.
82 * Can't have more of these than there are bits in an unsigned int
83 * since these are turned into bit masks during parsing and decoding.
85 * Furthermore, the values for YEAR, MONTH, DAY, HOUR, MINUTE, SECOND
86 * must be in the range 0..14 so that the associated bitmasks can fit
87 * into the left half of an INTERVAL's typmod value.
107 /* these are only for relative dates */
109 #define ABS_BEFORE 18
111 /* generic fields to help with parsing */
114 /* reserved for unrecognized string values */
115 #define UNKNOWN_FIELD 31
118 * Token field definitions for time parsing and decoding.
119 * These need to fit into the datetkn table type.
120 * At the moment, that means keep them within [-127,127].
121 * These are also used for bit masks in DecodeDateDelta()
122 * so actually restrict them to within [0,31] for now.
124 * Not all of these fields are used for masks in DecodeDateDelta
125 * so allow some larger than 31. - thomas 1997-11-17
136 #define DTK_SPECIAL 6
137 #define DTK_INVALID 7
138 #define DTK_CURRENT 8
143 #define DTK_YESTERDAY 13
145 #define DTK_TOMORROW 15
149 #define DTK_SECOND 18
150 #define DTK_MINUTE 19
155 #define DTK_QUARTER 24
157 #define DTK_DECADE 26
158 #define DTK_CENTURY 27
159 #define DTK_MILLENNIUM 28
160 #define DTK_MILLISEC 29
161 #define DTK_MICROSEC 30
162 #define DTK_JULIAN 31
166 #define DTK_TZ_HOUR 34
167 #define DTK_TZ_MINUTE 35
171 * Bit mask definitions for time parsing.
174 #define DTK_M(t) (0x01 << (t))
176 #define DTK_DATE_M (DTK_M(YEAR) | DTK_M(MONTH) | DTK_M(DAY))
177 #define DTK_TIME_M (DTK_M(HOUR) | DTK_M(MINUTE) | DTK_M(SECOND))
179 #define MAXDATELEN 51 /* maximum possible length of an input date
180 * string (not counting tr. null) */
181 #define MAXDATEFIELDS 25 /* maximum possible number of fields in a date
183 #define TOKMAXLEN 10 /* only this many chars are stored in
186 /* keep this struct small; it gets used a lot */
189 char token[TOKMAXLEN];
191 char value; /* this may be unsigned, alas */
196 * Macro to replace modf(), which is broken on some platforms.
197 * t = input and remainder
201 #define FMODULO(t,q,u) \
203 (q) = (((t) < 0) ? ceil((t) / (u)) : floor((t) / (u))); \
204 if ((q) != 0) (t) -= rint((q) * (u)); \
208 * Like FMODULO(), but work on the timestamp datatype (either int64 or float8).
209 * We assume that int64 follows the C99 semantics for division (negative
210 * quotients truncate towards zero).
212 #ifdef HAVE_INT64_TIMESTAMP
213 #define TMODULO(t,q,u) \
216 if ((q) != 0) (t) -= ((q) * (u)); \
219 #define TMODULO(t,q,u) \
221 (q) = (((t) < 0) ? ceil((t) / (u)) : floor((t) / (u))); \
222 if ((q) != 0) (t) -= rint((q) * (u)); \
227 * Date/time validation
228 * Include check for leap year.
231 extern const int day_tab[2][13];
233 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
236 /* Julian date support for date2j() and j2date()
238 * IS_VALID_JULIAN checks the minimum date exactly, but is a bit sloppy
239 * about the maximum, since it's far enough out to not be especially
243 #define JULIAN_MINYEAR (-4713)
244 #define JULIAN_MINMONTH (11)
245 #define JULIAN_MINDAY (24)
246 #define JULIAN_MAXYEAR (5874898)
248 #define IS_VALID_JULIAN(y,m,d) ((((y) > JULIAN_MINYEAR) \
249 || (((y) == JULIAN_MINYEAR) && (((m) > JULIAN_MINMONTH) \
250 || (((m) == JULIAN_MINMONTH) && ((d) >= JULIAN_MINDAY))))) \
251 && ((y) < JULIAN_MAXYEAR))
253 /* Julian-date equivalents of Day 0 in Unix and Postgres reckoning */
254 #define UNIX_EPOCH_JDATE 2440588 /* == date2j(1970, 1, 1) */
255 #define POSTGRES_EPOCH_JDATE 2451545 /* == date2j(2000, 1, 1) */
259 * Datetime input parsing routines (ParseDateTime, DecodeDateTime, etc)
260 * return zero or a positive value on success. On failure, they return
261 * one of these negative code values. DateTimeParseError may be used to
262 * produce a correct ereport.
264 #define DTERR_BAD_FORMAT (-1)
265 #define DTERR_FIELD_OVERFLOW (-2)
266 #define DTERR_MD_FIELD_OVERFLOW (-3) /* triggers hint about DateStyle */
267 #define DTERR_INTERVAL_OVERFLOW (-4)
268 #define DTERR_TZDISP_OVERFLOW (-5)
271 extern void GetCurrentDateTime(struct pg_tm * tm);
272 extern void GetCurrentTimeUsec(struct pg_tm * tm, fsec_t *fsec, int *tzp);
273 extern void j2date(int jd, int *year, int *month, int *day);
274 extern int date2j(int year, int month, int day);
276 extern int ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
277 char **field, int *ftype,
278 int maxfields, int *numfields);
279 extern int DecodeDateTime(char **field, int *ftype,
281 struct pg_tm * tm, fsec_t *fsec, int *tzp);
282 extern int DecodeTimeOnly(char **field, int *ftype,
284 struct pg_tm * tm, fsec_t *fsec, int *tzp);
285 extern int DecodeInterval(char **field, int *ftype,
287 struct pg_tm * tm, fsec_t *fsec);
288 extern void DateTimeParseError(int dterr, const char *str,
289 const char *datatype);
291 extern int DetermineTimeZoneOffset(struct pg_tm * tm, pg_tz *tzp);
293 extern int EncodeDateOnly(struct pg_tm * tm, int style, char *str);
294 extern int EncodeTimeOnly(struct pg_tm * tm, fsec_t fsec, int *tzp, int style, char *str);
295 extern int EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style, char *str);
296 extern int EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str);
298 extern int DecodeSpecial(int field, char *lowtoken, int *val);
299 extern int DecodeUnits(int field, char *lowtoken, int *val);
301 extern int j2day(int jd);
303 extern bool CheckDateTokenTables(void);
304 extern void InstallTimeZoneAbbrevs(tzEntry *abbrevs, int n);
306 extern Datum pg_timezone_abbrevs(PG_FUNCTION_ARGS);
307 extern Datum pg_timezone_names(PG_FUNCTION_ARGS);
309 #endif /* DATETIME_H */