line |
stmt |
bran |
cond |
sub |
pod |
time |
code |
1
|
|
|
|
|
|
|
=head1 NAME |
2
|
|
|
|
|
|
|
|
3
|
|
|
|
|
|
|
Date::ISO8601 - the three ISO 8601 numerical calendars |
4
|
|
|
|
|
|
|
|
5
|
|
|
|
|
|
|
=head1 SYNOPSIS |
6
|
|
|
|
|
|
|
|
7
|
|
|
|
|
|
|
use Date::ISO8601 qw(present_y); |
8
|
|
|
|
|
|
|
|
9
|
|
|
|
|
|
|
print present_y($y); |
10
|
|
|
|
|
|
|
|
11
|
|
|
|
|
|
|
use Date::ISO8601 |
12
|
|
|
|
|
|
|
qw(month_days cjdn_to_ymd ymd_to_cjdn present_ymd); |
13
|
|
|
|
|
|
|
|
14
|
|
|
|
|
|
|
$md = month_days(2000, 2); |
15
|
|
|
|
|
|
|
($y, $m, $d) = cjdn_to_ymd(2406029); |
16
|
|
|
|
|
|
|
$cjdn = ymd_to_cjdn(1875, 5, 20); |
17
|
|
|
|
|
|
|
print present_ymd(2406029); |
18
|
|
|
|
|
|
|
print present_ymd(1875, 5, 20); |
19
|
|
|
|
|
|
|
|
20
|
|
|
|
|
|
|
use Date::ISO8601 |
21
|
|
|
|
|
|
|
qw(year_days cjdn_to_yd yd_to_cjdn present_yd); |
22
|
|
|
|
|
|
|
|
23
|
|
|
|
|
|
|
$yd = year_days(2000); |
24
|
|
|
|
|
|
|
($y, $d) = cjdn_to_yd(2406029); |
25
|
|
|
|
|
|
|
$cjdn = yd_to_cjdn(1875, 140); |
26
|
|
|
|
|
|
|
print present_yd(2406029); |
27
|
|
|
|
|
|
|
print present_yd(1875, 140); |
28
|
|
|
|
|
|
|
|
29
|
|
|
|
|
|
|
use Date::ISO8601 |
30
|
|
|
|
|
|
|
qw(year_weeks cjdn_to_ywd ywd_to_cjdn present_ywd); |
31
|
|
|
|
|
|
|
|
32
|
|
|
|
|
|
|
$yw = year_weeks(2000); |
33
|
|
|
|
|
|
|
($y, $w, $d) = cjdn_to_ywd(2406029); |
34
|
|
|
|
|
|
|
$cjdn = ywd_to_cjdn(1875, 20, 4); |
35
|
|
|
|
|
|
|
print present_ywd(2406029); |
36
|
|
|
|
|
|
|
print present_ywd(1875, 20, 4); |
37
|
|
|
|
|
|
|
|
38
|
|
|
|
|
|
|
=head1 DESCRIPTION |
39
|
|
|
|
|
|
|
|
40
|
|
|
|
|
|
|
The international standard ISO 8601 "Data elements and interchange formats |
41
|
|
|
|
|
|
|
- Information interchange - Representation of dates and times" defines |
42
|
|
|
|
|
|
|
three distinct calendars by which days can be labelled. It also defines |
43
|
|
|
|
|
|
|
textual formats for the representation of dates in these calendars. |
44
|
|
|
|
|
|
|
This module provides functions to convert dates between these three |
45
|
|
|
|
|
|
|
calendars and Chronological Julian Day Numbers, which is a suitable |
46
|
|
|
|
|
|
|
format to do arithmetic with. It also supplies functions that describe |
47
|
|
|
|
|
|
|
the shape of these calendars, to assist in calendrical calculations. |
48
|
|
|
|
|
|
|
It also supplies functions to represent dates textually in the ISO |
49
|
|
|
|
|
|
|
8601 formats. ISO 8601 also covers time of day and time periods, but |
50
|
|
|
|
|
|
|
this module does nothing relating to those parts of the standard; this |
51
|
|
|
|
|
|
|
is only about labelling days. |
52
|
|
|
|
|
|
|
|
53
|
|
|
|
|
|
|
The first ISO 8601 calendar divides time up into years, months, and days. |
54
|
|
|
|
|
|
|
It corresponds exactly to the Gregorian calendar, invented by Aloysius |
55
|
|
|
|
|
|
|
Lilius and promulgated by Pope Gregory XIII in the late sixteenth century, |
56
|
|
|
|
|
|
|
with AD (CE) year numbering. This calendar is applied to all time, |
57
|
|
|
|
|
|
|
not just to dates after its invention nor just to years 1 and later. |
58
|
|
|
|
|
|
|
Thus for ancient dates it is the proleptic Gregorian calendar with |
59
|
|
|
|
|
|
|
astronomical year numbering. |
60
|
|
|
|
|
|
|
|
61
|
|
|
|
|
|
|
The second ISO 8601 calendar divides time up into the same years as |
62
|
|
|
|
|
|
|
the first, but divides the year directly into days, with no months. |
63
|
|
|
|
|
|
|
The standard calls this "ordinal dates". Ordinal dates are commonly |
64
|
|
|
|
|
|
|
referred to as "Julian dates", a mistake apparently deriving from true |
65
|
|
|
|
|
|
|
Julian Day Numbers, which divide time up solely into linearly counted |
66
|
|
|
|
|
|
|
days. |
67
|
|
|
|
|
|
|
|
68
|
|
|
|
|
|
|
The third ISO 8601 calendar divides time up into years, weeks, and days. |
69
|
|
|
|
|
|
|
The years approximate the years of the first two calendars, so they stay |
70
|
|
|
|
|
|
|
in step in the long term, but the boundaries differ. This week-based |
71
|
|
|
|
|
|
|
calendar is sometimes called "the ISO calendar", apparently in the belief |
72
|
|
|
|
|
|
|
that ISO 8601 does not define any other. It is also referred to as |
73
|
|
|
|
|
|
|
"business dates", because it is most used by certain businesses to whom |
74
|
|
|
|
|
|
|
the week is the most important temporal cycle. |
75
|
|
|
|
|
|
|
|
76
|
|
|
|
|
|
|
The Chronological Julian Day Number is an integral number labelling each |
77
|
|
|
|
|
|
|
day, where the day extends from midnight to midnight in whatever time zone |
78
|
|
|
|
|
|
|
is of interest. It is a linear count of days, where each day's number |
79
|
|
|
|
|
|
|
is one greater than the previous day's number. It is directly related to |
80
|
|
|
|
|
|
|
the Julian Date system: in the time zone of the prime meridian, the CJDN |
81
|
|
|
|
|
|
|
equals the JD at noon. By way of epoch, the day on which the Convention |
82
|
|
|
|
|
|
|
of the Metre was signed, which ISO 8601 defines to be 1875-05-20 (and |
83
|
|
|
|
|
|
|
1875-140 and 1875-W20-4), is CJDN 2406029. |
84
|
|
|
|
|
|
|
|
85
|
|
|
|
|
|
|
This module places no limit on the range of dates to which it may be |
86
|
|
|
|
|
|
|
applied. All function arguments are permitted to be C or |
87
|
|
|
|
|
|
|
C objects in order to achieve arbitrary range. Native Perl |
88
|
|
|
|
|
|
|
integers are also permitted, as a convenience when the range of dates |
89
|
|
|
|
|
|
|
being handled is known to be sufficiently small. |
90
|
|
|
|
|
|
|
|
91
|
|
|
|
|
|
|
=cut |
92
|
|
|
|
|
|
|
|
93
|
|
|
|
|
|
|
package Date::ISO8601; |
94
|
|
|
|
|
|
|
|
95
|
4
|
|
|
4
|
|
129747
|
{ use 5.006; } |
|
4
|
|
|
|
|
15
|
|
|
4
|
|
|
|
|
161
|
|
96
|
4
|
|
|
4
|
|
26
|
use warnings; |
|
4
|
|
|
|
|
6
|
|
|
4
|
|
|
|
|
154
|
|
97
|
4
|
|
|
4
|
|
21
|
use strict; |
|
4
|
|
|
|
|
8
|
|
|
4
|
|
|
|
|
177
|
|
98
|
|
|
|
|
|
|
|
99
|
4
|
|
|
4
|
|
22
|
use Carp qw(croak); |
|
4
|
|
|
|
|
14
|
|
|
4
|
|
|
|
|
396
|
|
100
|
|
|
|
|
|
|
|
101
|
|
|
|
|
|
|
our $VERSION = "0.004"; |
102
|
|
|
|
|
|
|
|
103
|
4
|
|
|
4
|
|
3524
|
use parent "Exporter"; |
|
4
|
|
|
|
|
1307
|
|
|
4
|
|
|
|
|
22
|
|
104
|
|
|
|
|
|
|
our @EXPORT_OK = qw( |
105
|
|
|
|
|
|
|
present_y |
106
|
|
|
|
|
|
|
month_days cjdn_to_ymd ymd_to_cjdn present_ymd |
107
|
|
|
|
|
|
|
year_days cjdn_to_yd yd_to_cjdn present_yd |
108
|
|
|
|
|
|
|
year_weeks cjdn_to_ywd ywd_to_cjdn present_ywd |
109
|
|
|
|
|
|
|
); |
110
|
|
|
|
|
|
|
|
111
|
|
|
|
|
|
|
# _numify(A): turn possibly-object number into native Perl integer |
112
|
|
|
|
|
|
|
|
113
|
|
|
|
|
|
|
sub _numify($) { |
114
|
1311
|
|
|
1311
|
|
155191
|
my($a) = @_; |
115
|
1311
|
100
|
|
|
|
4155
|
return ref($a) eq "" ? $a : $a->numify; |
116
|
|
|
|
|
|
|
} |
117
|
|
|
|
|
|
|
|
118
|
|
|
|
|
|
|
# _fdiv(A, B): divide A by B, flooring remainder |
119
|
|
|
|
|
|
|
# |
120
|
|
|
|
|
|
|
# B must be a positive Perl integer. A may be a Perl integer, Math::BigInt, |
121
|
|
|
|
|
|
|
# or Math::BigRat. The result has the same type as A. |
122
|
|
|
|
|
|
|
|
123
|
|
|
|
|
|
|
sub _fdiv($$) { |
124
|
554
|
|
|
554
|
|
732
|
my($a, $b) = @_; |
125
|
554
|
100
|
|
|
|
1195
|
if(ref($a) eq "Math::BigRat") { |
126
|
82
|
|
|
|
|
266
|
return ($a / $b)->bfloor; |
127
|
|
|
|
|
|
|
} else { |
128
|
472
|
100
|
|
|
|
1067
|
if($a < 0) { |
129
|
4
|
|
|
4
|
|
4357
|
use integer; |
|
4
|
|
|
|
|
38
|
|
|
4
|
|
|
|
|
21
|
|
130
|
29
|
|
|
|
|
1169
|
return -(($b - 1 - $a) / $b); |
131
|
|
|
|
|
|
|
} else { |
132
|
4
|
|
|
4
|
|
201
|
use integer; |
|
4
|
|
|
|
|
8
|
|
|
4
|
|
|
|
|
14
|
|
133
|
443
|
|
|
|
|
11192
|
return $a / $b; |
134
|
|
|
|
|
|
|
} |
135
|
|
|
|
|
|
|
} |
136
|
|
|
|
|
|
|
} |
137
|
|
|
|
|
|
|
|
138
|
|
|
|
|
|
|
# _fmod(A, B): A modulo B, flooring remainder |
139
|
|
|
|
|
|
|
# |
140
|
|
|
|
|
|
|
# B must be a positive Perl integer. A may be a Perl integer, Math::BigInt, |
141
|
|
|
|
|
|
|
# or Math::BigRat. The result has the same type as A. |
142
|
|
|
|
|
|
|
|
143
|
|
|
|
|
|
|
sub _fmod($$) { |
144
|
1339
|
|
|
1339
|
|
45168
|
my($a, $b) = @_; |
145
|
1339
|
100
|
|
|
|
2731
|
if(ref($a) eq "Math::BigRat") { |
146
|
153
|
|
|
|
|
479
|
return $a - $b * ($a / $b)->bfloor; |
147
|
|
|
|
|
|
|
} else { |
148
|
1186
|
|
|
|
|
5366
|
return $a % $b; |
149
|
|
|
|
|
|
|
} |
150
|
|
|
|
|
|
|
} |
151
|
|
|
|
|
|
|
|
152
|
|
|
|
|
|
|
=head1 FUNCTIONS |
153
|
|
|
|
|
|
|
|
154
|
|
|
|
|
|
|
Numbers in this API may be native Perl integers, C objects, |
155
|
|
|
|
|
|
|
or integer-valued C objects. All three types are acceptable |
156
|
|
|
|
|
|
|
for all parameters, in any combination. In all conversion functions, |
157
|
|
|
|
|
|
|
the most-significant part of the result (which is the only part with |
158
|
|
|
|
|
|
|
unlimited range) is of the same type as the most-significant part of |
159
|
|
|
|
|
|
|
the input. Less-significant parts of results (which have a small range) |
160
|
|
|
|
|
|
|
are consistently native Perl integers. |
161
|
|
|
|
|
|
|
|
162
|
|
|
|
|
|
|
All functions C if given invalid parameters. |
163
|
|
|
|
|
|
|
|
164
|
|
|
|
|
|
|
=head2 Years |
165
|
|
|
|
|
|
|
|
166
|
|
|
|
|
|
|
=over |
167
|
|
|
|
|
|
|
|
168
|
|
|
|
|
|
|
=item present_y(YEAR) |
169
|
|
|
|
|
|
|
|
170
|
|
|
|
|
|
|
Puts the given year number into ISO 8601 textual presentation format. |
171
|
|
|
|
|
|
|
For years [0, 9999] this is simply four digits. For years outside that |
172
|
|
|
|
|
|
|
range it is a sign followed by at least four digits. |
173
|
|
|
|
|
|
|
|
174
|
|
|
|
|
|
|
This is the minimum-length presentation format. If it is desired to |
175
|
|
|
|
|
|
|
use a form that is longer than necessary, such as to use at least five |
176
|
|
|
|
|
|
|
digits for all year numbers (as the Long Now Foundation does), then the |
177
|
|
|
|
|
|
|
right tool is C (see L). |
178
|
|
|
|
|
|
|
|
179
|
|
|
|
|
|
|
This format is unconditionally conformant to all versions of ISO 8601 |
180
|
|
|
|
|
|
|
for years [1583, 9999]. For years [0, 1582], preceding the historical |
181
|
|
|
|
|
|
|
introduction of the Gregorian calendar, it is conformant only where |
182
|
|
|
|
|
|
|
it is mutually agreed that such dates (represented in the proleptic |
183
|
|
|
|
|
|
|
Gregorian calendar) are acceptable. For years outside the range [0, |
184
|
|
|
|
|
|
|
9999], where the expanded format must be used, the result is only |
185
|
|
|
|
|
|
|
conformant to ISO 8601:2004 (earlier versions lacked these formats), |
186
|
|
|
|
|
|
|
and only where it is mutually agreed to use this format. |
187
|
|
|
|
|
|
|
|
188
|
|
|
|
|
|
|
=cut |
189
|
|
|
|
|
|
|
|
190
|
|
|
|
|
|
|
sub present_y($) { |
191
|
63
|
|
|
63
|
1
|
183265
|
my($y) = @_; |
192
|
63
|
|
|
|
|
312
|
my($sign, $digits) = ("$y" =~ /\A\+?(-?)0*([0-9]+?)\z/); |
193
|
63
|
100
|
|
|
|
1272
|
$digits = ("0" x (4 - length($digits))).$digits |
194
|
|
|
|
|
|
|
unless length($digits) >= 4; |
195
|
63
|
100
|
100
|
|
|
6866
|
$sign = "+" if $sign eq "" && length($digits) > 4; |
196
|
63
|
|
|
|
|
370
|
return $sign.$digits; |
197
|
|
|
|
|
|
|
} |
198
|
|
|
|
|
|
|
|
199
|
|
|
|
|
|
|
=back |
200
|
|
|
|
|
|
|
|
201
|
|
|
|
|
|
|
=head2 Gregorian calendar |
202
|
|
|
|
|
|
|
|
203
|
|
|
|
|
|
|
Each year is divided into twelve months, numbered [1, 12]; month number |
204
|
|
|
|
|
|
|
1 is January. Each month is divided into days, numbered sequentially |
205
|
|
|
|
|
|
|
from 1. The month lengths are irregular. The year numbers have |
206
|
|
|
|
|
|
|
unlimited range. |
207
|
|
|
|
|
|
|
|
208
|
|
|
|
|
|
|
=over |
209
|
|
|
|
|
|
|
|
210
|
|
|
|
|
|
|
=item month_days(YEAR, MONTH) |
211
|
|
|
|
|
|
|
|
212
|
|
|
|
|
|
|
The parameters identify a month, and the function returns the number of |
213
|
|
|
|
|
|
|
days in that month as a native Perl integer. |
214
|
|
|
|
|
|
|
|
215
|
|
|
|
|
|
|
=cut |
216
|
|
|
|
|
|
|
|
217
|
|
|
|
|
|
|
sub _year_leap($) { |
218
|
627
|
|
|
627
|
|
937
|
my($y) = @_; |
219
|
627
|
|
66
|
|
|
1049
|
return _fmod($y, 4) == 0 && |
220
|
|
|
|
|
|
|
(_fmod($y, 100) != 0 || _fmod($y, 400) == 0); |
221
|
|
|
|
|
|
|
} |
222
|
|
|
|
|
|
|
|
223
|
|
|
|
|
|
|
{ |
224
|
|
|
|
|
|
|
my @month_length = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31); |
225
|
|
|
|
|
|
|
sub month_days($$) { |
226
|
57
|
|
|
57
|
1
|
132001
|
my($y, $m) = @_; |
227
|
57
|
50
|
33
|
|
|
275
|
croak "month number $m is out of the range [1, 12]" |
228
|
|
|
|
|
|
|
unless $m >= 1 && $m <= 12; |
229
|
57
|
100
|
|
|
|
110
|
if($m == 2) { |
230
|
24
|
100
|
|
|
|
43
|
return _year_leap($y) ? 29 : 28; |
231
|
|
|
|
|
|
|
} else { |
232
|
33
|
|
|
|
|
105
|
return $month_length[$m - 1]; |
233
|
|
|
|
|
|
|
} |
234
|
|
|
|
|
|
|
} |
235
|
|
|
|
|
|
|
} |
236
|
|
|
|
|
|
|
|
237
|
|
|
|
|
|
|
{ |
238
|
|
|
|
|
|
|
my @nonleap_monthstarts = |
239
|
|
|
|
|
|
|
(0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365); |
240
|
|
|
|
|
|
|
my @leap_monthstarts = |
241
|
|
|
|
|
|
|
(0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366); |
242
|
|
|
|
|
|
|
sub _year_monthstarts($) { |
243
|
72
|
|
|
72
|
|
91
|
my($y) = @_; |
244
|
72
|
100
|
|
|
|
118
|
return _year_leap($y) ? |
245
|
|
|
|
|
|
|
\@leap_monthstarts : \@nonleap_monthstarts; |
246
|
|
|
|
|
|
|
} |
247
|
|
|
|
|
|
|
} |
248
|
|
|
|
|
|
|
|
249
|
|
|
|
|
|
|
=item cjdn_to_ymd(CJDN) |
250
|
|
|
|
|
|
|
|
251
|
|
|
|
|
|
|
This function takes a Chronological Julian Day Number and returns a list |
252
|
|
|
|
|
|
|
of a year, month, and day. |
253
|
|
|
|
|
|
|
|
254
|
|
|
|
|
|
|
=cut |
255
|
|
|
|
|
|
|
|
256
|
|
|
|
|
|
|
sub cjdn_to_yd($); |
257
|
|
|
|
|
|
|
|
258
|
|
|
|
|
|
|
sub cjdn_to_ymd($) { |
259
|
35
|
|
|
35
|
1
|
27733
|
my($cjdn) = @_; |
260
|
35
|
|
|
|
|
82
|
my($y, $d) = cjdn_to_yd($cjdn); |
261
|
35
|
|
|
|
|
8374
|
my $monthstarts = _year_monthstarts($y); |
262
|
35
|
|
|
|
|
12185
|
my $m = 1; |
263
|
35
|
|
|
|
|
90
|
while($d > $monthstarts->[$m]) { |
264
|
154
|
|
|
|
|
290
|
$m++; |
265
|
|
|
|
|
|
|
} |
266
|
35
|
|
|
|
|
157
|
return ($y, $m, $d - $monthstarts->[$m - 1]); |
267
|
|
|
|
|
|
|
} |
268
|
|
|
|
|
|
|
|
269
|
|
|
|
|
|
|
=item ymd_to_cjdn(YEAR, MONTH, DAY) |
270
|
|
|
|
|
|
|
|
271
|
|
|
|
|
|
|
This performs the reverse of the translation that C does. |
272
|
|
|
|
|
|
|
It takes year, month, and day numbers, and returns the corresponding CJDN. |
273
|
|
|
|
|
|
|
|
274
|
|
|
|
|
|
|
=cut |
275
|
|
|
|
|
|
|
|
276
|
|
|
|
|
|
|
sub yd_to_cjdn($$); |
277
|
|
|
|
|
|
|
|
278
|
|
|
|
|
|
|
sub ymd_to_cjdn($$$) { |
279
|
39
|
|
|
39
|
1
|
22867
|
my($y, $m, $d) = @_; |
280
|
39
|
100
|
100
|
|
|
558
|
croak "month number $m is out of the range [1, 12]" |
281
|
|
|
|
|
|
|
unless $m >= 1 && $m <= 12; |
282
|
37
|
|
|
|
|
73
|
$m = _numify($m); |
283
|
37
|
|
|
|
|
70
|
my $monthstarts = _year_monthstarts($y); |
284
|
37
|
|
|
|
|
11628
|
my $md = $monthstarts->[$m] - $monthstarts->[$m - 1]; |
285
|
37
|
100
|
100
|
|
|
716
|
croak "day number $d is out of the range [1, $md]" |
286
|
|
|
|
|
|
|
unless $d >= 1 && $d <= $md; |
287
|
33
|
|
|
|
|
50
|
$d = _numify($d); |
288
|
33
|
|
|
|
|
90
|
return yd_to_cjdn($y, $monthstarts->[$m - 1] + $d); |
289
|
|
|
|
|
|
|
} |
290
|
|
|
|
|
|
|
|
291
|
|
|
|
|
|
|
=item present_ymd(CJDN) |
292
|
|
|
|
|
|
|
|
293
|
|
|
|
|
|
|
=item present_ymd(YEAR, MONTH, DAY) |
294
|
|
|
|
|
|
|
|
295
|
|
|
|
|
|
|
Puts the given date into ISO 8601 Gregorian textual presentation format. |
296
|
|
|
|
|
|
|
The `extended' format (with "-" separators) is used. The conformance |
297
|
|
|
|
|
|
|
notes for C apply to this function also. |
298
|
|
|
|
|
|
|
|
299
|
|
|
|
|
|
|
If the date is given as a (YEAR, MONTH, DAY) triplet then these are not |
300
|
|
|
|
|
|
|
checked for consistency. The MONTH and DAY values are only checked to |
301
|
|
|
|
|
|
|
ensure that they fit into the fixed number of digits. This allows the |
302
|
|
|
|
|
|
|
use of this function on data other than actual Gregorian dates. |
303
|
|
|
|
|
|
|
|
304
|
|
|
|
|
|
|
=cut |
305
|
|
|
|
|
|
|
|
306
|
|
|
|
|
|
|
sub present_ymd($;$$) { |
307
|
11
|
|
|
11
|
1
|
1771
|
my($y, $m, $d); |
308
|
11
|
100
|
|
|
|
22
|
if(@_ == 1) { |
309
|
2
|
|
|
|
|
6
|
($y, $m, $d) = cjdn_to_ymd($_[0]); |
310
|
|
|
|
|
|
|
} else { |
311
|
9
|
|
|
|
|
11
|
($y, $m, $d) = @_; |
312
|
9
|
100
|
100
|
|
|
354
|
croak "month number $m is out of the displayable range" |
313
|
|
|
|
|
|
|
unless $m >= 0 && $m < 100; |
314
|
7
|
100
|
100
|
|
|
230
|
croak "day number $d is out of the displayable range" |
315
|
|
|
|
|
|
|
unless $d >= 0 && $d < 100; |
316
|
|
|
|
|
|
|
} |
317
|
7
|
|
|
|
|
15
|
return sprintf("%s-%02d-%02d", present_y($y), |
318
|
|
|
|
|
|
|
_numify($m), _numify($d)); |
319
|
|
|
|
|
|
|
} |
320
|
|
|
|
|
|
|
|
321
|
|
|
|
|
|
|
=back |
322
|
|
|
|
|
|
|
|
323
|
|
|
|
|
|
|
=head2 Ordinal dates |
324
|
|
|
|
|
|
|
|
325
|
|
|
|
|
|
|
Each year is divided into days, numbered sequentially from 1. The year |
326
|
|
|
|
|
|
|
lengths are irregular. The years correspond exactly to those of the |
327
|
|
|
|
|
|
|
Gregorian calendar. |
328
|
|
|
|
|
|
|
|
329
|
|
|
|
|
|
|
=over |
330
|
|
|
|
|
|
|
|
331
|
|
|
|
|
|
|
=item year_days(YEAR) |
332
|
|
|
|
|
|
|
|
333
|
|
|
|
|
|
|
The parameter identifies a year, and the function returns the number of |
334
|
|
|
|
|
|
|
days in that year as a native Perl integer. |
335
|
|
|
|
|
|
|
|
336
|
|
|
|
|
|
|
=cut |
337
|
|
|
|
|
|
|
|
338
|
|
|
|
|
|
|
sub year_days($) { |
339
|
513
|
|
|
513
|
1
|
115087
|
my($y) = @_; |
340
|
513
|
100
|
|
|
|
1139
|
return _year_leap($y) ? 366 : 365; |
341
|
|
|
|
|
|
|
} |
342
|
|
|
|
|
|
|
|
343
|
4
|
|
|
4
|
|
4524
|
use constant GREGORIAN_ZERO_CJDN => 1721060; # 0000-001 |
|
4
|
|
|
|
|
18
|
|
|
4
|
|
|
|
|
522
|
|
344
|
|
|
|
|
|
|
|
345
|
|
|
|
|
|
|
=item cjdn_to_yd(CJDN) |
346
|
|
|
|
|
|
|
|
347
|
|
|
|
|
|
|
This function takes a Chronological Julian Day Number and returns a |
348
|
|
|
|
|
|
|
list of a year and ordinal day. |
349
|
|
|
|
|
|
|
|
350
|
|
|
|
|
|
|
=cut |
351
|
|
|
|
|
|
|
|
352
|
|
|
|
|
|
|
sub cjdn_to_yd($) { |
353
|
129
|
|
|
129
|
1
|
32329
|
my($cjdn) = @_; |
354
|
4
|
|
|
4
|
|
20
|
use integer; |
|
4
|
|
|
|
|
7
|
|
|
4
|
|
|
|
|
22
|
|
355
|
129
|
|
|
|
|
412
|
my $d = $cjdn - GREGORIAN_ZERO_CJDN; |
356
|
129
|
|
|
|
|
31392
|
my $qcents = _fdiv($d, 365*400 + 97); |
357
|
129
|
|
|
|
|
33325
|
$d = _numify($d - $qcents * (365*400 + 97)); |
358
|
129
|
|
|
|
|
2008
|
my $y = $d / 366; |
359
|
129
|
|
|
|
|
221
|
my $leaps = ($y + 3) / 4; |
360
|
129
|
100
|
|
|
|
393
|
$leaps -= ($leaps - 1) / 25 unless $leaps == 0; |
361
|
129
|
|
|
|
|
388
|
$d -= 365 * $y + $leaps; |
362
|
129
|
|
|
|
|
253
|
my $yd = year_days($y); |
363
|
129
|
100
|
|
|
|
394
|
if($d >= $yd) { |
364
|
49
|
|
|
|
|
69
|
$d -= $yd; |
365
|
49
|
|
|
|
|
117
|
$y++; |
366
|
|
|
|
|
|
|
} |
367
|
129
|
|
|
|
|
342
|
return ($qcents*400 + $y, 1 + $d); |
368
|
|
|
|
|
|
|
} |
369
|
|
|
|
|
|
|
|
370
|
|
|
|
|
|
|
=item yd_to_cjdn(YEAR, DAY) |
371
|
|
|
|
|
|
|
|
372
|
|
|
|
|
|
|
This performs the reverse of the translation that C does. |
373
|
|
|
|
|
|
|
It takes year and ordinal day numbers, and returns the corresponding CJDN. |
374
|
|
|
|
|
|
|
|
375
|
|
|
|
|
|
|
=cut |
376
|
|
|
|
|
|
|
|
377
|
|
|
|
|
|
|
sub yd_to_cjdn($$) { |
378
|
360
|
|
|
360
|
1
|
33603
|
my($y, $d) = @_; |
379
|
4
|
|
|
4
|
|
1438
|
use integer; |
|
4
|
|
|
|
|
6
|
|
|
4
|
|
|
|
|
13
|
|
380
|
360
|
|
|
|
|
635
|
my $qcents = _fdiv($y, 400); |
381
|
360
|
|
|
|
|
28727
|
$y = _numify($y - $qcents * 400); |
382
|
360
|
|
|
|
|
2380
|
my $yd = year_days($y); |
383
|
360
|
100
|
100
|
|
|
2464
|
croak "day number $d is out of the range [1, $yd]" |
384
|
|
|
|
|
|
|
unless $d >= 1 && $d <= $yd; |
385
|
357
|
|
|
|
|
804
|
$d = _numify($d); |
386
|
357
|
|
|
|
|
640
|
my $leaps = ($y + 3) / 4; |
387
|
357
|
100
|
|
|
|
794
|
$leaps -= ($leaps - 1) / 25 unless $leaps == 0; |
388
|
357
|
|
|
|
|
1204
|
return (GREGORIAN_ZERO_CJDN + 365*$y + $leaps + ($d - 1)) + |
389
|
|
|
|
|
|
|
$qcents * (365*400 + 97); |
390
|
|
|
|
|
|
|
} |
391
|
|
|
|
|
|
|
|
392
|
|
|
|
|
|
|
=item present_yd(CJDN) |
393
|
|
|
|
|
|
|
|
394
|
|
|
|
|
|
|
=item present_yd(YEAR, DAY) |
395
|
|
|
|
|
|
|
|
396
|
|
|
|
|
|
|
Puts the given date into ISO 8601 ordinal textual presentation format. |
397
|
|
|
|
|
|
|
The `extended' format (with "-" separators) is used. The conformance |
398
|
|
|
|
|
|
|
notes for C apply to this function also. |
399
|
|
|
|
|
|
|
|
400
|
|
|
|
|
|
|
If the date is given as a (YEAR, DAY) pair then these are not checked |
401
|
|
|
|
|
|
|
for consistency. The DAY value is only checked to ensure that it fits |
402
|
|
|
|
|
|
|
into the fixed number of digits. This allows the use of this function |
403
|
|
|
|
|
|
|
on data other than actual ordinal dates. |
404
|
|
|
|
|
|
|
|
405
|
|
|
|
|
|
|
=cut |
406
|
|
|
|
|
|
|
|
407
|
|
|
|
|
|
|
sub present_yd($;$) { |
408
|
9
|
|
|
9
|
1
|
3061
|
my($y, $d); |
409
|
9
|
100
|
|
|
|
29
|
if(@_ == 1) { |
410
|
2
|
|
|
|
|
7
|
($y, $d) = cjdn_to_yd($_[0]); |
411
|
|
|
|
|
|
|
} else { |
412
|
7
|
|
|
|
|
17
|
($y, $d) = @_; |
413
|
7
|
100
|
100
|
|
|
463
|
croak "day number $d is out of the displayable range" |
414
|
|
|
|
|
|
|
unless $d >= 0 && $d < 1000; |
415
|
|
|
|
|
|
|
} |
416
|
7
|
|
|
|
|
19
|
return sprintf("%s-%03d", present_y($y), _numify($d)); |
417
|
|
|
|
|
|
|
} |
418
|
|
|
|
|
|
|
|
419
|
|
|
|
|
|
|
=back |
420
|
|
|
|
|
|
|
|
421
|
|
|
|
|
|
|
=head2 Week-based calendar |
422
|
|
|
|
|
|
|
|
423
|
|
|
|
|
|
|
Each year is divided into weeks, numbered sequentially from 1. Each week |
424
|
|
|
|
|
|
|
is divided into seven days, numbered [1, 7]; day number 1 is Monday. |
425
|
|
|
|
|
|
|
The year lengths are irregular. The year numbers have unlimited range. |
426
|
|
|
|
|
|
|
|
427
|
|
|
|
|
|
|
The years correspond to those of the Gregorian calendar. Each week is |
428
|
|
|
|
|
|
|
associated with the Gregorian year that contains its Thursday and hence |
429
|
|
|
|
|
|
|
contains the majority of its days. |
430
|
|
|
|
|
|
|
|
431
|
|
|
|
|
|
|
=over |
432
|
|
|
|
|
|
|
|
433
|
|
|
|
|
|
|
=item year_weeks(YEAR) |
434
|
|
|
|
|
|
|
|
435
|
|
|
|
|
|
|
The parameter identifies a year, and the function returns the number of |
436
|
|
|
|
|
|
|
weeks in that year as a native Perl integer. |
437
|
|
|
|
|
|
|
|
438
|
|
|
|
|
|
|
=cut |
439
|
|
|
|
|
|
|
|
440
|
|
|
|
|
|
|
# _year_phase(YEAR): find day of week of first day of year |
441
|
|
|
|
|
|
|
# |
442
|
|
|
|
|
|
|
# The argument must be a native Perl integer. The return value is |
443
|
|
|
|
|
|
|
# zero-based, in the range 0 = Monday to 6 = Sunday. |
444
|
|
|
|
|
|
|
|
445
|
|
|
|
|
|
|
sub _year_phase($) { |
446
|
234
|
|
|
234
|
|
317
|
my($y) = @_; |
447
|
234
|
|
|
|
|
481
|
return yd_to_cjdn($y, 1) % 7; |
448
|
|
|
|
|
|
|
} |
449
|
|
|
|
|
|
|
|
450
|
|
|
|
|
|
|
sub year_weeks($) { |
451
|
169
|
|
|
169
|
1
|
123293
|
my($y) = @_; |
452
|
169
|
|
|
|
|
332
|
$y = _numify(_fmod($y, 400)); |
453
|
169
|
|
|
|
|
1669
|
my $phase = _year_phase($y); |
454
|
169
|
100
|
66
|
|
|
816
|
return $phase == 3 || ($phase == 2 && _year_leap($y)) ? 53 : 52; |
455
|
|
|
|
|
|
|
} |
456
|
|
|
|
|
|
|
|
457
|
|
|
|
|
|
|
=item cjdn_to_ywd(CJDN) |
458
|
|
|
|
|
|
|
|
459
|
|
|
|
|
|
|
This function takes a Chronological Julian Day Number and returns a list |
460
|
|
|
|
|
|
|
of a year, week, and day. |
461
|
|
|
|
|
|
|
|
462
|
|
|
|
|
|
|
=cut |
463
|
|
|
|
|
|
|
|
464
|
|
|
|
|
|
|
sub cjdn_to_ywd($) { |
465
|
65
|
|
|
65
|
1
|
86266
|
my($cjdn) = @_; |
466
|
65
|
|
|
|
|
195
|
my($y, $d) = cjdn_to_yd($cjdn); |
467
|
65
|
|
|
|
|
15549
|
my $py = _numify(_fmod($y, 400)); |
468
|
65
|
|
|
|
|
2694
|
my $phase = _year_phase($py); |
469
|
65
|
100
|
|
|
|
175
|
my $start_wk1 = ($phase <= 3 ? 1 : 8) - $phase; |
470
|
65
|
|
|
|
|
146
|
my $w = _fdiv($d - $start_wk1, 7); |
471
|
65
|
100
|
|
|
|
188
|
if($w == -1) { |
|
|
100
|
|
|
|
|
|
472
|
15
|
|
|
|
|
49
|
$y--; |
473
|
15
|
|
|
|
|
836
|
$w = year_weeks($py - 1); |
474
|
|
|
|
|
|
|
} elsif($w >= year_weeks($py)) { |
475
|
3
|
|
|
|
|
11
|
$y++; |
476
|
3
|
|
|
|
|
145
|
$w = 1; |
477
|
|
|
|
|
|
|
} else { |
478
|
47
|
|
|
|
|
67
|
$w++; |
479
|
|
|
|
|
|
|
} |
480
|
65
|
|
|
|
|
337
|
return ($y, $w, ($d - $start_wk1) % 7 + 1); |
481
|
|
|
|
|
|
|
} |
482
|
|
|
|
|
|
|
|
483
|
|
|
|
|
|
|
=item ywd_to_cjdn(YEAR, WEEK, DAY) |
484
|
|
|
|
|
|
|
|
485
|
|
|
|
|
|
|
This performs the reverse of the translation that C does. |
486
|
|
|
|
|
|
|
It takes year, week, and day numbers, and returns the corresponding CJDN. |
487
|
|
|
|
|
|
|
|
488
|
|
|
|
|
|
|
=cut |
489
|
|
|
|
|
|
|
|
490
|
|
|
|
|
|
|
sub ywd_to_cjdn($$$) { |
491
|
68
|
|
|
68
|
1
|
74339
|
my($y, $w, $d) = @_; |
492
|
68
|
|
|
|
|
163
|
my $yw = year_weeks($y); |
493
|
68
|
100
|
100
|
|
|
860
|
croak "week number $w is out of the range [1, $yw]" |
494
|
|
|
|
|
|
|
unless $w >= 1 && $w <= $yw; |
495
|
65
|
100
|
100
|
|
|
543
|
croak "day number $d is out of the range [1, 7]" |
496
|
|
|
|
|
|
|
unless $d >= 1 && $d <= 7; |
497
|
63
|
|
|
|
|
113
|
my $start_cjdn = yd_to_cjdn($y, 1); |
498
|
63
|
|
|
|
|
16593
|
my $phase = _fmod($start_cjdn, 7); |
499
|
63
|
100
|
|
|
|
17541
|
return $start_cjdn + |
500
|
|
|
|
|
|
|
(($phase <= 3 ? -8 : -1) - $phase + |
501
|
|
|
|
|
|
|
_numify($w)*7 + _numify($d)); |
502
|
|
|
|
|
|
|
} |
503
|
|
|
|
|
|
|
|
504
|
|
|
|
|
|
|
=item present_ywd(CJDN) |
505
|
|
|
|
|
|
|
|
506
|
|
|
|
|
|
|
=item present_ywd(YEAR, WEEK, DAY) |
507
|
|
|
|
|
|
|
|
508
|
|
|
|
|
|
|
Puts the given date into ISO 8601 week-based textual presentation format. |
509
|
|
|
|
|
|
|
The `extended' format (with "-" separators) is used. The conformance |
510
|
|
|
|
|
|
|
notes for C apply to this function also. |
511
|
|
|
|
|
|
|
|
512
|
|
|
|
|
|
|
If the date is given as a (YEAR, WEEK, DAY) triplet then these are not |
513
|
|
|
|
|
|
|
checked for consistency. The WEEK and DAY values are only checked to |
514
|
|
|
|
|
|
|
ensure that they fit into the fixed number of digits. This allows the |
515
|
|
|
|
|
|
|
use of this function on data other than actual week-based dates. |
516
|
|
|
|
|
|
|
|
517
|
|
|
|
|
|
|
=cut |
518
|
|
|
|
|
|
|
|
519
|
|
|
|
|
|
|
sub present_ywd($;$$) { |
520
|
11
|
|
|
11
|
1
|
3184
|
my($y, $w, $d); |
521
|
11
|
100
|
|
|
|
26
|
if(@_ == 1) { |
522
|
2
|
|
|
|
|
7
|
($y, $w, $d) = cjdn_to_ywd($_[0]); |
523
|
|
|
|
|
|
|
} else { |
524
|
9
|
|
|
|
|
16
|
($y, $w, $d) = @_; |
525
|
9
|
100
|
100
|
|
|
412
|
croak "week number $w is out of the displayable range" |
526
|
|
|
|
|
|
|
unless $w >= 0 && $w < 100; |
527
|
7
|
100
|
100
|
|
|
316
|
croak "day number $d is out of the displayable range" |
528
|
|
|
|
|
|
|
unless $d >= 0 && $d < 10; |
529
|
|
|
|
|
|
|
} |
530
|
7
|
|
|
|
|
16
|
return sprintf("%s-W%02d-%d", present_y($y), _numify($w), _numify($d)); |
531
|
|
|
|
|
|
|
} |
532
|
|
|
|
|
|
|
|
533
|
|
|
|
|
|
|
=back |
534
|
|
|
|
|
|
|
|
535
|
|
|
|
|
|
|
=head1 SEE ALSO |
536
|
|
|
|
|
|
|
|
537
|
|
|
|
|
|
|
L, |
538
|
|
|
|
|
|
|
L |
539
|
|
|
|
|
|
|
|
540
|
|
|
|
|
|
|
=head1 AUTHOR |
541
|
|
|
|
|
|
|
|
542
|
|
|
|
|
|
|
Andrew Main (Zefram) |
543
|
|
|
|
|
|
|
|
544
|
|
|
|
|
|
|
=head1 COPYRIGHT |
545
|
|
|
|
|
|
|
|
546
|
|
|
|
|
|
|
Copyright (C) 2006, 2007, 2009, 2011 |
547
|
|
|
|
|
|
|
Andrew Main (Zefram) |
548
|
|
|
|
|
|
|
|
549
|
|
|
|
|
|
|
=head1 LICENSE |
550
|
|
|
|
|
|
|
|
551
|
|
|
|
|
|
|
This module is free software; you can redistribute it and/or modify it |
552
|
|
|
|
|
|
|
under the same terms as Perl itself. |
553
|
|
|
|
|
|
|
|
554
|
|
|
|
|
|
|
=cut |
555
|
|
|
|
|
|
|
|
556
|
|
|
|
|
|
|
1; |