1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
/****************************************************************************
**
** Copyright (C) 2018 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qglobal.h"
#include "qjalalicalendar_p.h"
#include "qjalalicalendar_data_p.h"
#include "qcalendarmath_p.h"
#include <QtCore/qmath.h>
QT_BEGIN_NAMESPACE
using namespace QRoundingDown;
// Constants
static const qint64 cycleDays = 1029983;
static const int cycleYears = 2820;
static const double yearLength = 365.24219858156028368; // 365 + leapRatio;
static const qint64 jalaliEpoch = 2121446; // 475/01/01 AP, start of 2820 cycle
// Calendar implementation
static inline int cycle(qint64 jdn)
{
return qDiv(jdn - jalaliEpoch, cycleDays);
}
qint64 cycleStart(int cycleNo)
{
return jalaliEpoch + cycleNo * cycleDays;
}
qint64 firstDayOfYear(int year, int cycleNo)
{
qint64 firstDOYinEra = static_cast<qint64>(qFloor(year * yearLength));
return jalaliEpoch + cycleNo * cycleDays + firstDOYinEra;
}
/*!
\since 5.14
\class QJalaliCalendar
\inmodule QtCore
\brief The QJalaliCalendar class provides Jalali (Hijri Shamsi) calendar
system implementation.
\section1 Solar Hijri Calendar System
The Solar Hijri calendar, also called the Solar Hejri calendar, Shamsi
Hijri calendar or Jalali calendar, is the official calendar of Iran and
Afghanistan. It begins on the vernal equinox (Nowruz) as determined by
astronomical calculation for the Iran Standard Time meridian
(52.5°E or GMT+3.5h). This determination of starting moment is more accurate
than the Gregorian calendar for predicting the date of the vernal equinox,
because it uses astronomical observations rather than mathematical rules.
\section2 Calendar Organization
Each of the twelve months corresponds with a zodiac sign. The first six
months have 31 days, the next five have 30 days, and the last month has 29
days in usual years but 30 days in leap years. The New Year's Day always
falls on the March equinox.
\section2 Leap Year Rules
The Solar Hijri calendar produces a five-year leap year interval after about
every seven four-year leap year intervals. It usually follows a 33-year
cycle with occasional interruptions by single 29-year or 37-year subcycles.
The reason for this behavior is that it tracks the observed vernal equinox.
By contrast, some less accurate predictive algorithms are in use based
on confusion between the average tropical year (365.2422 days, approximated
with near 128-year cycles or 2820-year great cycles) and the mean interval
between spring equinoxes (365.2424 days, approximated with a near 33-year
cycle).
Source: \l {https://en.wikipedia.org/wiki/Solar_Hijri_calendar}{Wikipedia
page on Solar Hijri Calendar}
*/
QJalaliCalendar::QJalaliCalendar()
: QCalendarBackend(QStringLiteral("Jalali"), QCalendar::System::Jalali)
{
registerAlias(QStringLiteral("Persian"));
}
QString QJalaliCalendar::name() const
{
return QStringLiteral("Jalali");
}
QCalendar::System QJalaliCalendar::calendarSystem() const
{
return QCalendar::System::Jalali;
}
bool QJalaliCalendar::isLeapYear(int year) const
{
if (year == QCalendar::Unspecified)
return false;
if (year < 0)
year++;
return qMod((year + 2346) * 683, 2820) < 683;
}
bool QJalaliCalendar::isLunar() const
{
return false;
}
bool QJalaliCalendar::isLuniSolar() const
{
return false;
}
bool QJalaliCalendar::isSolar() const
{
return true;
}
bool QJalaliCalendar::dateToJulianDay(int year, int month, int day, qint64 *jd) const
{
Q_ASSERT(jd);
if (!isDateValid(year, month, day))
return false;
const int y = year - (year < 0 ? 474 : 475);
const int c = qDiv(y, cycleYears);
const int yearInCycle = y - c * cycleYears;
int dayInYear = day;
for (int i = 1; i < month; ++i)
dayInYear += daysInMonth(i, year);
*jd = firstDayOfYear(yearInCycle, c) + dayInYear - 1;
return true;
}
QCalendar::YearMonthDay QJalaliCalendar::julianDayToDate(qint64 jd) const
{
const int c = cycle(jd);
int yearInCycle = qFloor((jd - cycleStart(c)) / yearLength);
int year = yearInCycle + 475 + c * cycleYears;
int day = jd - firstDayOfYear(yearInCycle, c) + 1;
if (day > daysInYear(year <= 0 ? year - 1 : year)) {
year++;
day = 1;
}
if (year <= 0)
year--;
int month;
for (month = 1; month < 12; ++month) {
const int last = daysInMonth(month, year);
if (day <= last)
break;
day -= last;
}
return QCalendar::YearMonthDay(year, month, day);
}
int QJalaliCalendar::daysInMonth(int month, int year) const
{
if (year && month > 0 && month <= 12)
return month < 7 ? 31 : month < 12 || isLeapYear(year) ? 30 : 29;
return 0;
}
const QCalendarLocale *QJalaliCalendar::localeMonthIndexData() const
{
return locale_data;
}
const ushort *QJalaliCalendar::localeMonthData() const
{
return months_data;
}
QT_END_NAMESPACE
|
