1 //
2 // LocalDateTime.h
3 //
4 // Library: Foundation
5 // Package: DateTime
6 // Module:  LocalDateTime
7 //
8 // Definition of the LocalDateTime 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_LocalDateTime_INCLUDED
18 #define Foundation_LocalDateTime_INCLUDED
19 
20 
21 #include "Poco/Foundation.h"
22 #include "Poco/DateTime.h"
23 
24 
25 namespace Poco {
26 
27 
28 class Foundation_API LocalDateTime
29 	/// This class represents an instant in local time
30 	/// (as opposed to UTC), expressed in years, months, days,
31 	/// hours, minutes, seconds and milliseconds based on the
32 	/// Gregorian calendar.
33 	///
34 	/// In addition to the date and time, the class also
35 	/// maintains a time zone differential, which denotes
36 	/// the difference in seconds from UTC to local time,
37 	/// i.e. UTC = local time - time zone differential.
38 	///
39 	/// Although LocalDateTime supports relational and arithmetic
40 	/// operators, all date/time comparisons and date/time arithmetic
41 	/// should be done in UTC, using the DateTime or Timestamp
42 	/// class for better performance. The relational operators
43 	/// normalize the dates/times involved to UTC before carrying out
44 	/// the comparison.
45 	///
46 	/// The time zone differential is based on the input date and
47 	/// time and current time zone. A number of constructors accept
48 	/// an explicit time zone differential parameter. These should
49 	/// not be used since daylight savings time processing is impossible
50 	/// since the time zone is unknown. Each of the constructors
51 	/// accepting a tzd parameter have been marked as deprecated and
52 	/// may be removed in a future revision.
53 {
54 public:
55 	LocalDateTime();
56 		/// Creates a LocalDateTime with the current date/time
57 		/// for the current time zone.
58 
59 	LocalDateTime(int year, int month, int day, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microsecond = 0);
60 		/// Creates a LocalDateTime for the given Gregorian local date and time.
61 		///   * year is from 0 to 9999.
62 		///   * month is from 1 to 12.
63 		///   * day is from 1 to 31.
64 		///   * hour is from 0 to 23.
65 		///   * minute is from 0 to 59.
66 		///   * second is from 0 to 60 (allowing leap seconds).
67 		///   * millisecond is from 0 to 999.
68 		///   * microsecond is from 0 to 999.
69 
70 	//@ deprecated
71 	LocalDateTime(int tzd, int year, int month, int day, int hour, int minute, int second, int millisecond, int microsecond);
72 		/// Creates a LocalDateTime for the given Gregorian date and time in the
73 		/// time zone denoted by the time zone differential in tzd.
74 		///   * tzd is in seconds.
75 		///   * year is from 0 to 9999.
76 		///   * month is from 1 to 12.
77 		///   * day is from 1 to 31.
78 		///   * hour is from 0 to 23.
79 		///   * minute is from 0 to 59.
80 		///   * second is from 0 to 60 (allowing leap seconds).
81 		///   * millisecond is from 0 to 999.
82 		///   * microsecond is from 0 to 999.
83 
84 	LocalDateTime(const DateTime& dateTime);
85 		/// Creates a LocalDateTime from the UTC time given in dateTime,
86 		/// using the time zone differential of the current time zone.
87 
88 	//@ deprecated
89 	LocalDateTime(int tzd, const DateTime& dateTime);
90 		/// Creates a LocalDateTime from the UTC time given in dateTime,
91 		/// using the given time zone differential. Adjusts dateTime
92 		/// for the given time zone differential.
93 
94 	//@ deprecated
95 	LocalDateTime(int tzd, const DateTime& dateTime, bool adjust);
96 		/// Creates a LocalDateTime from the UTC time given in dateTime,
97 		/// using the given time zone differential. If adjust is true,
98 		/// adjusts dateTime for the given time zone differential.
99 
100 	LocalDateTime(double julianDay);
101 		/// Creates a LocalDateTime for the given Julian day in the local time zone.
102 
103 	//@ deprecated
104 	LocalDateTime(int tzd, double julianDay);
105 		/// Creates a LocalDateTime for the given Julian day in the time zone
106 		/// denoted by the time zone differential in tzd.
107 
108 	LocalDateTime(const LocalDateTime& dateTime);
109 		/// Copy constructor. Creates the LocalDateTime from another one.
110 
111 	~LocalDateTime();
112 		/// Destroys the LocalDateTime.
113 
114 	LocalDateTime& operator = (const LocalDateTime& dateTime);
115 		/// Assigns another LocalDateTime.
116 
117 	LocalDateTime& operator = (const Timestamp& timestamp);
118 		/// Assigns a timestamp
119 
120 	LocalDateTime& operator = (double julianDay);
121 		/// Assigns a Julian day in the local time zone.
122 
123 	LocalDateTime& assign(int year, int month, int day, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microseconds = 0);
124 		/// Assigns a Gregorian local date and time.
125 		///   * year is from 0 to 9999.
126 		///   * month is from 1 to 12.
127 		///   * day is from 1 to 31.
128 		///   * hour is from 0 to 23.
129 		///   * minute is from 0 to 59.
130 		///   * second is from 0 to 60 (allowing leap seconds).
131 		///   * millisecond is from 0 to 999.
132 		///   * microsecond is from 0 to 999.
133 
134 	//@ deprecated
135 	LocalDateTime& assign(int tzd, int year, int month, int day, int hour, int minute, int second, int millisecond, int microseconds);
136 		/// Assigns a Gregorian local date and time in the time zone denoted by
137 		/// the time zone differential in tzd.
138 		///   * tzd is in seconds.
139 		///   * year is from 0 to 9999.
140 		///   * month is from 1 to 12.
141 		///   * day is from 1 to 31.
142 		///   * hour is from 0 to 23.
143 		///   * minute is from 0 to 59.
144 		///   * second is from 0 to 60 (allowing leap seconds).
145 		///   * millisecond is from 0 to 999.
146 		///   * microsecond is from 0 to 999.
147 
148 	//@ deprecated
149 	LocalDateTime& assign(int tzd, double julianDay);
150 		/// Assigns a Julian day in the time zone denoted by the
151 		/// time zone differential in tzd.
152 
153 	void swap(LocalDateTime& dateTime);
154 		/// Swaps the LocalDateTime with another one.
155 
156 	int year() const;
157 		/// Returns the year.
158 
159 	int month() const;
160 		/// Returns the month (1 to 12).
161 
162 	int week(int firstDayOfWeek = DateTime::MONDAY) const;
163 		/// Returns the week number within the year.
164 		/// FirstDayOfWeek should be either SUNDAY (0) or MONDAY (1).
165 		/// The returned week number will be from 0 to 53. Week number 1 is the week
166 		/// containing January 4. This is in accordance to ISO 8601.
167 		///
168 		/// The following example assumes that firstDayOfWeek is MONDAY. For 2005, which started
169 		/// on a Saturday, week 1 will be the week starting on Monday, January 3.
170 		/// January 1 and 2 will fall within week 0 (or the last week of the previous year).
171 		///
172 		/// For 2007, which starts on a Monday, week 1 will be the week starting on Monday, January 1.
173 		/// There will be no week 0 in 2007.
174 
175 	int day() const;
176 		/// Returns the day within the month (1 to 31).
177 
178 	int dayOfWeek() const;
179 		/// Returns the weekday (0 to 6, where
180 		/// 0 = Sunday, 1 = Monday, ..., 6 = Saturday).
181 
182 	int dayOfYear() const;
183 		/// Returns the number of the day in the year.
184 		/// January 1 is 1, February 1 is 32, etc.
185 
186 	int hour() const;
187 		/// Returns the hour (0 to 23).
188 
189 	int hourAMPM() const;
190 		/// Returns the hour (0 to 12).
191 
192 	bool isAM() const;
193 		/// Returns true if hour < 12;
194 
195 	bool isPM() const;
196 		/// Returns true if hour >= 12.
197 
198 	int minute() const;
199 		/// Returns the minute (0 to 59).
200 
201 	int second() const;
202 		/// Returns the second (0 to 59).
203 
204 	int millisecond() const;
205 		/// Returns the millisecond (0 to 999)
206 
207 	int microsecond() const;
208 		/// Returns the microsecond (0 to 999)
209 
210 	double julianDay() const;
211 		/// Returns the Julian day for the date.
212 
213 	int tzd() const;
214 		/// Returns the time zone differential.
215 
216 	DateTime utc() const;
217 		/// Returns the UTC equivalent for the local date and time.
218 
219 	Timestamp timestamp() const;
220 		/// Returns the date and time expressed as a Timestamp.
221 
222 	Timestamp::UtcTimeVal utcTime() const;
223 		/// Returns the UTC equivalent for the local date and time.
224 
225 	bool operator == (const LocalDateTime& dateTime) const;
226 	bool operator != (const LocalDateTime& dateTime) const;
227 	bool operator <  (const LocalDateTime& dateTime) const;
228 	bool operator <= (const LocalDateTime& dateTime) const;
229 	bool operator >  (const LocalDateTime& dateTime) const;
230 	bool operator >= (const LocalDateTime& dateTime) const;
231 
232 	LocalDateTime  operator +  (const Timespan& span) const;
233 	LocalDateTime  operator -  (const Timespan& span) const;
234 	Timespan       operator -  (const LocalDateTime& dateTime) const;
235 	LocalDateTime& operator += (const Timespan& span);
236 	LocalDateTime& operator -= (const Timespan& span);
237 
238 protected:
239 	LocalDateTime(Timestamp::UtcTimeVal utcTime, Timestamp::TimeDiff diff, int tzd);
240 
241 	void determineTzd(bool adjust = false);
242 		/// Recalculate the tzd based on the _dateTime member based
243 		/// on the current timezone using the Standard C runtime functions.
244 		/// If adjust is true, then adjustForTzd() is called after the
245 		/// differential is calculated.
246 
247 	void adjustForTzd();
248 		/// Adjust the _dateTime member based on the _tzd member.
249 
250 	std::time_t dstOffset(int& dstOffset) const;
251 		/// Determine the DST offset for the current date/time.
252 
253 private:
254 	DateTime _dateTime;
255 	int      _tzd;
256 
257 	friend class DateTimeFormatter;
258 	friend class DateTimeParser;
259 };
260 
261 
262 //
263 // inlines
264 //
year()265 inline int LocalDateTime::year() const
266 {
267 	return _dateTime.year();
268 }
269 
270 
month()271 inline int LocalDateTime::month() const
272 {
273 	return _dateTime.month();
274 }
275 
276 
week(int firstDayOfWeek)277 inline int LocalDateTime::week(int firstDayOfWeek) const
278 {
279 	return _dateTime.week(firstDayOfWeek);
280 }
281 
282 
day()283 inline int LocalDateTime::day() const
284 {
285 	return _dateTime.day();
286 }
287 
288 
dayOfWeek()289 inline int LocalDateTime::dayOfWeek() const
290 {
291 	return _dateTime.dayOfWeek();
292 }
293 
294 
dayOfYear()295 inline int LocalDateTime::dayOfYear() const
296 {
297 	return _dateTime.dayOfYear();
298 }
299 
300 
hour()301 inline int LocalDateTime::hour() const
302 {
303 	return _dateTime.hour();
304 }
305 
306 
hourAMPM()307 inline int LocalDateTime::hourAMPM() const
308 {
309 	return _dateTime.hourAMPM();
310 }
311 
312 
isAM()313 inline bool LocalDateTime::isAM() const
314 {
315 	return _dateTime.isAM();
316 }
317 
318 
isPM()319 inline bool LocalDateTime::isPM() const
320 {
321 	return _dateTime.isPM();
322 }
323 
324 
minute()325 inline int LocalDateTime::minute() const
326 {
327 	return _dateTime.minute();
328 }
329 
330 
second()331 inline int LocalDateTime::second() const
332 {
333 	return _dateTime.second();
334 }
335 
336 
millisecond()337 inline int LocalDateTime::millisecond() const
338 {
339 	return _dateTime.millisecond();
340 }
341 
342 
microsecond()343 inline int LocalDateTime::microsecond() const
344 {
345 	return _dateTime.microsecond();
346 }
347 
348 
julianDay()349 inline double LocalDateTime::julianDay() const
350 {
351 	return _dateTime.julianDay();
352 }
353 
354 
tzd()355 inline int LocalDateTime::tzd() const
356 {
357 	return _tzd;
358 }
359 
360 
timestamp()361 inline Timestamp LocalDateTime::timestamp() const
362 {
363 	return Timestamp::fromUtcTime(_dateTime.utcTime());
364 }
365 
366 
utcTime()367 inline Timestamp::UtcTimeVal LocalDateTime::utcTime() const
368 {
369 	return _dateTime.utcTime() - ((Timestamp::TimeDiff) _tzd)*10000000;
370 }
371 
372 
adjustForTzd()373 inline void LocalDateTime::adjustForTzd()
374 {
375 	_dateTime += Timespan(((Timestamp::TimeDiff) _tzd)*Timespan::SECONDS);
376 }
377 
378 
swap(LocalDateTime & d1,LocalDateTime & d2)379 inline void swap(LocalDateTime& d1, LocalDateTime& d2)
380 {
381 	d1.swap(d2);
382 }
383 
384 
385 } // namespace Poco
386 
387 
388 #endif // Foundation_LocalDateTime_INCLUDED
389