1//
2// DateTime.h
3//
4// Library: Foundation
5// Package: DateTime
6// Module: DateTime
7//
8// Definition of the DateTime class.
9//
10// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
11// and Contributors.
12//
13// SPDX-License-Identifier: BSL-1.0
14//
15
16
17#ifndef Foundation_DateTime_INCLUDED
18#define Foundation_DateTime_INCLUDED
19
20
21#include "Poco/Foundation.h"
22#include "Poco/Timestamp.h"
23#include "Poco/Timespan.h"
24
25
26namespace Poco {
27
28
29class Foundation_API DateTime
30 /// This class represents an instant in time, expressed
31 /// in years, months, days, hours, minutes, seconds
32 /// and milliseconds based on the Gregorian calendar.
33 /// The class is mainly useful for conversions between
34 /// UTC, Julian day and Gregorian calendar dates.
35 ///
36 /// The date and time stored in a DateTime is always in UTC
37 /// (Coordinated Universal Time) and thus independent of the
38 /// timezone in effect on the system.
39 ///
40 /// Conversion calculations are based on algorithms
41 /// collected and described by Peter Baum at
42 /// http://vsg.cape.com/~pbaum/date/date0.htm
43 ///
44 /// Internally, this class stores a date/time in two
45 /// forms (UTC and broken down) for performance reasons. Only use
46 /// this class for conversions between date/time representations.
47 /// Use the Timestamp class for everything else.
48 ///
49 /// Notes:
50 /// * Zero is a valid year (in accordance with ISO 8601 and astronomical year numbering)
51 /// * Year zero (0) is a leap year
52 /// * Negative years (years preceding 1 BC) are not supported
53 ///
54 /// For more information, please see:
55 /// * http://en.wikipedia.org/wiki/Gregorian_Calendar
56 /// * http://en.wikipedia.org/wiki/Julian_day
57 /// * http://en.wikipedia.org/wiki/UTC
58 /// * http://en.wikipedia.org/wiki/ISO_8601
59{
60public:
61 enum Months
62 /// Symbolic names for month numbers (1 to 12).
63 {
64 JANUARY = 1,
65 FEBRUARY,
66 MARCH,
67 APRIL,
68 MAY,
69 JUNE,
70 JULY,
71 AUGUST,
72 SEPTEMBER,
73 OCTOBER,
74 NOVEMBER,
75 DECEMBER
76 };
77
78 enum DaysOfWeek
79 /// Symbolic names for week day numbers (0 to 6).
80 {
81 SUNDAY = 0,
82 MONDAY,
83 TUESDAY,
84 WEDNESDAY,
85 THURSDAY,
86 FRIDAY,
87 SATURDAY
88 };
89
90 DateTime();
91 /// Creates a DateTime for the current date and time.
92
93 DateTime(const Timestamp& timestamp);
94 /// Creates a DateTime for the date and time given in
95 /// a Timestamp.
96
97 DateTime(int year, int month, int day, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microsecond = 0);
98 /// Creates a DateTime for the given Gregorian date and time.
99 /// * year is from 0 to 9999.
100 /// * month is from 1 to 12.
101 /// * day is from 1 to 31.
102 /// * hour is from 0 to 23.
103 /// * minute is from 0 to 59.
104 /// * second is from 0 to 59.
105 /// * millisecond is from 0 to 999.
106 /// * microsecond is from 0 to 999.
107 /// Throws an InvalidArgumentException if an argument date is out of range.
108
109 DateTime(double julianDay);
110 /// Creates a DateTime for the given Julian day.
111
112 DateTime(Timestamp::UtcTimeVal utcTime, Timestamp::TimeDiff diff);
113 /// Creates a DateTime from an UtcTimeVal and a TimeDiff.
114 ///
115 /// Mainly used internally by DateTime and friends.
116
117 DateTime(const DateTime& dateTime);
118 /// Copy constructor. Creates the DateTime from another one.
119
120 ~DateTime();
121 /// Destroys the DateTime.
122
123 DateTime& operator = (const DateTime& dateTime);
124 /// Assigns another DateTime.
125
126 DateTime& operator = (const Timestamp& timestamp);
127 /// Assigns a Timestamp.
128
129 DateTime& operator = (double julianDay);
130 /// Assigns a Julian day.
131
132 DateTime& assign(int year, int month, int day, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microseconds = 0);
133 /// Assigns a Gregorian date and time.
134 /// * year is from 0 to 9999.
135 /// * month is from 1 to 12.
136 /// * day is from 1 to 31.
137 /// * hour is from 0 to 23.
138 /// * minute is from 0 to 59.
139 /// * second is from 0 to 59.
140 /// * millisecond is from 0 to 999.
141 /// * microsecond is from 0 to 999.
142 /// Throws an InvalidArgumentException if an argument date is out of range.
143
144 void swap(DateTime& dateTime);
145 /// Swaps the DateTime with another one.
146
147 int year() const;
148 /// Returns the year.
149
150 int month() const;
151 /// Returns the month (1 to 12).
152
153 int week(int firstDayOfWeek = MONDAY) const;
154 /// Returns the week number within the year.
155 /// FirstDayOfWeek should be either SUNDAY (0) or MONDAY (1).
156 /// The returned week number will be from 0 to 53. Week number 1 is the week
157 /// containing January 4. This is in accordance to ISO 8601.
158 ///
159 /// The following example assumes that firstDayOfWeek is MONDAY. For 2005, which started
160 /// on a Saturday, week 1 will be the week starting on Monday, January 3.
161 /// January 1 and 2 will fall within week 0 (or the last week of the previous year).
162 ///
163 /// For 2007, which starts on a Monday, week 1 will be the week starting on Monday, January 1.
164 /// There will be no week 0 in 2007.
165
166 int day() const;
167 /// Returns the day within the month (1 to 31).
168
169 int dayOfWeek() const;
170 /// Returns the weekday (0 to 6, where
171 /// 0 = Sunday, 1 = Monday, ..., 6 = Saturday).
172
173 int dayOfYear() const;
174 /// Returns the number of the day in the year.
175 /// January 1 is 1, February 1 is 32, etc.
176
177 int hour() const;
178 /// Returns the hour (0 to 23).
179
180 int hourAMPM() const;
181 /// Returns the hour (0 to 12).
182
183 bool isAM() const;
184 /// Returns true if hour < 12;
185
186 bool isPM() const;
187 /// Returns true if hour >= 12.
188
189 int minute() const;
190 /// Returns the minute (0 to 59).
191
192 int second() const;
193 /// Returns the second (0 to 59).
194
195 int millisecond() const;
196 /// Returns the millisecond (0 to 999)
197
198 int microsecond() const;
199 /// Returns the microsecond (0 to 999)
200
201 double julianDay() const;
202 /// Returns the julian day for the date and time.
203
204 Timestamp timestamp() const;
205 /// Returns the date and time expressed as a Timestamp.
206
207 Timestamp::UtcTimeVal utcTime() const;
208 /// Returns the date and time expressed in UTC-based
209 /// time. UTC base time is midnight, October 15, 1582.
210 /// Resolution is 100 nanoseconds.
211
212 bool operator == (const DateTime& dateTime) const;
213 bool operator != (const DateTime& dateTime) const;
214 bool operator < (const DateTime& dateTime) const;
215 bool operator <= (const DateTime& dateTime) const;
216 bool operator > (const DateTime& dateTime) const;
217 bool operator >= (const DateTime& dateTime) const;
218
219 DateTime operator + (const Timespan& span) const;
220 DateTime operator - (const Timespan& span) const;
221 Timespan operator - (const DateTime& dateTime) const;
222 DateTime& operator += (const Timespan& span);
223 DateTime& operator -= (const Timespan& span);
224
225 void makeUTC(int tzd);
226 /// Converts a local time into UTC, by applying the given time zone differential.
227
228 void makeLocal(int tzd);
229 /// Converts a UTC time into a local time, by applying the given time zone differential.
230
231 static bool isLeapYear(int year);
232 /// Returns true if the given year is a leap year;
233 /// false otherwise.
234
235 static int daysOfMonth(int year, int month);
236 /// Returns the number of days in the given month
237 /// and year. Month is from 1 to 12.
238
239 static bool isValid(int year, int month, int day, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microsecond = 0);
240 /// Checks if the given date and time is valid
241 /// (all arguments are within a proper range).
242 ///
243 /// Returns true if all arguments are valid, false otherwise.
244
245protected:
246 static double toJulianDay(Timestamp::UtcTimeVal utcTime);
247 /// Computes the Julian day for an UTC time.
248
249 static double toJulianDay(int year, int month, int day, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microsecond = 0);
250 /// Computes the Julian day for a Gregorian calendar date and time.
251 /// See <http://vsg.cape.com/~pbaum/date/jdimp.htm>, section 2.3.1 for the algorithm.
252
253 static Timestamp::UtcTimeVal toUtcTime(double julianDay);
254 /// Computes the UTC time for a Julian day.
255
256 void computeGregorian(double julianDay);
257 /// Computes the Gregorian date for the given Julian day.
258 /// See <http://vsg.cape.com/~pbaum/date/injdimp.htm>, section 3.3.1 for the algorithm.
259
260 void computeDaytime();
261 /// Extracts the daytime (hours, minutes, seconds, etc.) from the stored utcTime.
262
263private:
264 void checkLimit(short& lower, short& higher, short limit);
265 void normalize();
266 ///utility functions used to correct the overflow in computeGregorian
267
268 Timestamp::UtcTimeVal _utcTime;
269 short _year;
270 short _month;
271 short _day;
272 short _hour;
273 short _minute;
274 short _second;
275 short _millisecond;
276 short _microsecond;
277};
278
279
280//
281// inlines
282//
283
284
285inline double DateTime::toJulianDay(Timestamp::UtcTimeVal utcTime)
286{
287 double utcDays = double(utcTime)/864000000000.0;
288 return utcDays + 2299160.5; // first day of Gregorian reform (Oct 15 1582)
289}
290
291
292inline Timestamp::UtcTimeVal DateTime::toUtcTime(double julianDay)
293{
294 return Timestamp::UtcTimeVal((julianDay - 2299160.5)*864000000000.0);
295}
296
297
298inline Timestamp DateTime::timestamp() const
299{
300 return Timestamp::fromUtcTime(_utcTime);
301}
302
303
304inline Timestamp::UtcTimeVal DateTime::utcTime() const
305{
306 return _utcTime;
307}
308
309
310inline int DateTime::year() const
311{
312 return _year;
313}
314
315
316inline int DateTime::month() const
317{
318 return _month;
319}
320
321
322inline int DateTime::day() const
323{
324 return _day;
325}
326
327
328inline int DateTime::hour() const
329{
330 return _hour;
331}
332
333
334inline int DateTime::hourAMPM() const
335{
336 if (_hour < 1)
337 return 12;
338 else if (_hour > 12)
339 return _hour - 12;
340 else
341 return _hour;
342}
343
344
345inline bool DateTime::isAM() const
346{
347 return _hour < 12;
348}
349
350
351inline bool DateTime::isPM() const
352{
353 return _hour >= 12;
354}
355
356
357inline int DateTime::minute() const
358{
359 return _minute;
360}
361
362
363inline int DateTime::second() const
364{
365 return _second;
366}
367
368
369inline int DateTime::millisecond() const
370{
371 return _millisecond;
372}
373
374
375inline int DateTime::microsecond() const
376{
377 return _microsecond;
378}
379
380
381inline bool DateTime::operator == (const DateTime& dateTime) const
382{
383 return _utcTime == dateTime._utcTime;
384}
385
386
387inline bool DateTime::operator != (const DateTime& dateTime) const
388{
389 return _utcTime != dateTime._utcTime;
390}
391
392
393inline bool DateTime::operator < (const DateTime& dateTime) const
394{
395 return _utcTime < dateTime._utcTime;
396}
397
398
399inline bool DateTime::operator <= (const DateTime& dateTime) const
400{
401 return _utcTime <= dateTime._utcTime;
402}
403
404
405inline bool DateTime::operator > (const DateTime& dateTime) const
406{
407 return _utcTime > dateTime._utcTime;
408}
409
410
411inline bool DateTime::operator >= (const DateTime& dateTime) const
412{
413 return _utcTime >= dateTime._utcTime;
414}
415
416
417inline bool DateTime::isLeapYear(int year)
418{
419 return (year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0);
420}
421
422
423inline void swap(DateTime& d1, DateTime& d2)
424{
425 d1.swap(d2);
426}
427
428
429} // namespace Poco
430
431
432#endif // Foundation_DateTime_INCLUDED
433