| 1 | |
| 2 | =head1 NAME |
| 3 | |
| 4 | Date::Calendar::Year - Implements embedded "year" objects for Date::Calendar |
| 5 | |
| 6 | =head1 MOTTO |
| 7 | |
| 8 | There is more than one way to do it - this is just one of them! |
| 9 | |
| 10 | =head1 PREFACE |
| 11 | |
| 12 | Note that Date::Calendar::Year (and Date::Calendar) can only deal |
| 13 | with years lying within the range [1583..2299]. |
| 14 | |
| 15 | =head1 SYNOPSIS |
| 16 | |
| 17 | use Date::Calendar::Year qw( check_year empty_period ); |
| 18 | use Date::Calendar::Year qw( :all ); # same as above |
| 19 | |
| 20 | check_year(YEAR|DATE); # dies if year < 1583 or year > 2299 |
| 21 | empty_period(); # warns about empty interval if $^W is set |
| 22 | |
| 23 | $index = $year->date2index(YEAR,MONTH,DAY|DATE); |
| 24 | $date = $year->index2date(INDEX); |
| 25 | |
| 26 | use Date::Calendar::Profiles qw( $Profiles ); |
| 27 | $year_2000_US_FL = Date::Calendar::Year->new( 2000, $Profiles->{'US-FL'} [,LANG] ); |
| 28 | $year_2001_DE_NW = Date::Calendar::Year->new( 2001, $Profiles->{'DE-NW'} [,LANG] ); |
| 29 | |
| 30 | $year = Date::Calendar::Year->new( 2001, {} ); |
| 31 | $year->init( 2002, $Profiles->{'DE-SN'} [,LANG] ); |
| 32 | |
| 33 | $vector = $year->vec_full(); # vector of full holidays |
| 34 | $vector = $year->vec_half(); # vector of half holidays |
| 35 | $vector = $year->vec_work(); # NOT a vector of workdays but a workspace! |
| 36 | $size = $year->val_days(); # number of days in that year, size of vectors |
| 37 | $base = $year->val_base(); # number of days for [year,1,1] since [1,1,1] |
| 38 | $number = $year->val_year(); # the year's number itself |
| 39 | $number = $year->year(); # alias for val_year() |
| 40 | |
| 41 | @names = $year->labels(YEAR,MONTH,DAY|DATE); |
| 42 | @holidays = $year->labels(); |
| 43 | $holidays = $year->labels(); |
| 44 | |
| 45 | @dates = $year->search(PATTERN); |
| 46 | $dates = $year->search(PATTERN); |
| 47 | |
| 48 | $days = $year->delta_workdays(YEAR,MONTH1,DAY1|DATE1 |
| 49 | ,YEAR,MONTH2,DAY2|DATE2 |
| 50 | ,FLAG1,FLAG2); |
| 51 | |
| 52 | ($date,$rest,$sign) = $year->add_delta_workdays(YEAR,MONTH,DAY|DATE |
| 53 | ,DELTA,SIGN); |
| 54 | |
| 55 | $flag = $year->is_full(YEAR,MONTH,DAY|DATE); |
| 56 | $flag = $year->is_half(YEAR,MONTH,DAY|DATE); |
| 57 | $flag = $year->is_work(YEAR,MONTH,DAY|DATE); |
| 58 | |
| 59 | =head1 INTERFACE |
| 60 | |
| 61 | Note that whenever a year number, a date, a time or a combined |
| 62 | date and time are expected as input parameters by one of the |
| 63 | methods of this class, you can always pass a Date::Calc[::Object] |
| 64 | date object or an array reference (of an array of appropriate |
| 65 | length) instead! |
| 66 | |
| 67 | See L<Date::Calc::Object(3)> for more details. |
| 68 | |
| 69 | So instead of calling a given method like this: |
| 70 | |
| 71 | $object->method1( $year,$month,$day ); |
| 72 | $object->method2( $year1,$month1,$day1, $year2,$month2,$day2 ); |
| 73 | $object->method3( $year1, $year2, $year3 ); |
| 74 | |
| 75 | You can also call it like so: |
| 76 | |
| 77 | $object->method1( $date ); |
| 78 | $object->method1( [1964,1,3] ); |
| 79 | |
| 80 | $object->method2( $year1,$month1,$day1, $date2 ); |
| 81 | $object->method2( $date1, $year2,$month2,$day2 ); |
| 82 | $object->method2( $date1, $date2 ); |
| 83 | $object->method2( $year1,$month1,$day1, [2001,3,17] ); |
| 84 | $object->method2( [1964,1,3], $year2,$month2,$day2 ); |
| 85 | $object->method2( [1964,1,3], [2001,3,17] ); |
| 86 | $object->method2( $date1, [2001,3,17] ); |
| 87 | $object->method2( [1964,1,3], $date2 ); |
| 88 | |
| 89 | $object->method3( $year1, $date2, [2001,3,17] ); |
| 90 | |
| 91 | And similarly if a time or a combined date and time are expected. |
| 92 | |
| 93 | If you substitute an expected year number by an anonymous array |
| 94 | (this is the recommended way of writing date constants, for |
| 95 | increased readability of your programs), it must contain three |
| 96 | values, nevertheless (otherwise the use of an anonymous array |
| 97 | would be pointless). |
| 98 | |
| 99 | Don't confuse year numbers and their substitutes (a date object |
| 100 | or an array reference) with Date::Calendar::Year objects, which |
| 101 | are a totally different thing! |
| 102 | |
| 103 | But incidentally C<:-)>, you may also pass a Date::Calendar::Year |
| 104 | object whenever a year number is expected. However, and perhaps |
| 105 | against your expectations at times, only the year number from |
| 106 | that object will be used, not the year object itself (the year |
| 107 | object in question might be using the wrong profile!). |
| 108 | |
| 109 | Moreover, whenever a method of this class returns a date, it |
| 110 | does so by returning a Date::Calc[::Object] date object. |
| 111 | |
| 112 | =head1 IMPLEMENTATION |
| 113 | |
| 114 | Each Date::Calendar::Year object consists mainly of three bit |
| 115 | vectors, plus some administrative attributes, all stored in a |
| 116 | (blessed) hash. |
| 117 | |
| 118 | All three bit vectors contain as many bits as there are days |
| 119 | in the corresponding year, i.e., either 365 or 366. |
| 120 | |
| 121 | The first bit vector, called "FULL", contains set bits for |
| 122 | Saturdays, Sundays and all "full" legal holidays (i.e., |
| 123 | days off, on which you usually do not work). |
| 124 | |
| 125 | The second bit vector, called "HALF", contains set bits for |
| 126 | all "half" holidays, i.e., holidays where you get only half |
| 127 | a day off from work. |
| 128 | |
| 129 | The third and last bit vector, called "WORK", is used as a |
| 130 | workspace, in which various calculations are performed |
| 131 | throughout this module. |
| 132 | |
| 133 | Its name does B<NOT> come from "working days" (as you might |
| 134 | think), but from "workspace". |
| 135 | |
| 136 | It only so happens that it is used to calculate the working |
| 137 | days sometimes, at some places in this module. |
| 138 | |
| 139 | But you are free to use it yourself, for whatever calculation |
| 140 | you would like to carry out yourself. |
| 141 | |
| 142 | The two other bit vectors, "FULL" and "HALF", should never be |
| 143 | changed, unless you know B<EXACTLY> what you're doing! |
| 144 | |
| 145 | =head1 DESCRIPTION |
| 146 | |
| 147 | Functions |
| 148 | |
| 149 | =over 2 |
| 150 | |
| 151 | =item * |
| 152 | |
| 153 | C<check_year(YEAR);> |
| 154 | |
| 155 | This function checks that the given year lies in the permitted |
| 156 | range [1583..2299]. It returns nothing in case of success, and |
| 157 | throws an exception ("given year out of range [1583..2299]") |
| 158 | otherwise. |
| 159 | |
| 160 | =item * |
| 161 | |
| 162 | C<empty_period();> |
| 163 | |
| 164 | This function issues a warning (from the perspective of the |
| 165 | caller of a Date::* module) that the given range of dates is |
| 166 | empty ("dates interval is empty"), provided that warnings are |
| 167 | enabled (i.e., "C<$^W>" is true). |
| 168 | |
| 169 | This function is currently used by the method "delta_workdays()" |
| 170 | in this class, and by its equivalent from the Date::Calendar |
| 171 | module. |
| 172 | |
| 173 | It is called whenever the range of dates of which the difference |
| 174 | in working days is to be calculated is empty. This can happen for |
| 175 | instance if you specify two adjacent dates both of which are not |
| 176 | to be included in the difference. |
| 177 | |
| 178 | =back |
| 179 | |
| 180 | Methods |
| 181 | |
| 182 | =over 2 |
| 183 | |
| 184 | =item * |
| 185 | |
| 186 | C<$index = $year-E<gt>date2index(YEAR,MONTH,DAY|DATE);> |
| 187 | |
| 188 | This method converts a given date into the number of the day in |
| 189 | that year (this is sometimes also referred to as the "julian" |
| 190 | date), i.e., a number between 0 (for January 1st) and the number |
| 191 | of days in the given year minus one, i.e., 364 or 365 (for |
| 192 | December 31st). |
| 193 | |
| 194 | You may need this in order to access the bit vectors returned |
| 195 | by the methods "vec_full()", "vec_half()" and "vec_work()". |
| 196 | |
| 197 | Note that there are shorthand methods in this module called |
| 198 | "is_full()", "is_half()" and "is_work()", which serve to test |
| 199 | individual bits of the three bit vectors which are a part of |
| 200 | each Date::Calendar::Year object. |
| 201 | |
| 202 | An exception ("given year != object's year") is thrown if the |
| 203 | year associated with the year object itself and the year from |
| 204 | the given date do not match. |
| 205 | |
| 206 | An exception ("invalid date") is also thrown if the given |
| 207 | arguments do not constitute a valid date, or ("given year |
| 208 | out of range [1583..2299]") if the given year lies outside |
| 209 | of the permitted range. |
| 210 | |
| 211 | =item * |
| 212 | |
| 213 | C<$date = $year-E<gt>index2date(INDEX);> |
| 214 | |
| 215 | This method converts an index (or "julian date") for the |
| 216 | given year back into a date. |
| 217 | |
| 218 | An exception ("invalid index") is thrown if the given index |
| 219 | is outside of the permitted range for the given year, i.e., |
| 220 | C<[0..364]> or C<[0..365]>. |
| 221 | |
| 222 | Note that this method returns a Date::Calc B<OBJECT>! |
| 223 | |
| 224 | =item * |
| 225 | |
| 226 | C<$year_2000_US_FL = Date::Calendar::Year-E<gt>new( 2000, $Profiles-E<gt>{'US-FL'} [,LANG] );> |
| 227 | |
| 228 | C<$year_2001_DE_NW = Date::Calendar::Year-E<gt>new( 2001, $Profiles-E<gt>{'DE-NW'} [,LANG] );> |
| 229 | |
| 230 | C<$year = Date::Calendar::Year-E<gt>new( 2001, {} );> |
| 231 | |
| 232 | This is the constructor method. Call it to create a new |
| 233 | Date::Calendar::Year object. |
| 234 | |
| 235 | The first argument must be a year number in the range |
| 236 | [1583..2299]. |
| 237 | |
| 238 | The second argument must be the reference of a hash, |
| 239 | which usually contains names of holidays and commemorative |
| 240 | days as keys and strings containing the date or formula |
| 241 | for each holiday as values. |
| 242 | |
| 243 | Reading this hash and initializing the object's internal |
| 244 | data is performed by an extra method, called "init()", |
| 245 | which is called internally by the constructor method, |
| 246 | and which is described immediately below, after this |
| 247 | method. |
| 248 | |
| 249 | In case you call the "init()" method yourself, explicitly, |
| 250 | after creating the object, you can pass an empty profile |
| 251 | (e.g., just an empty anonymous hash) to the "new()" method |
| 252 | in order to improve performance. |
| 253 | |
| 254 | The third argument is optional, and must consist of |
| 255 | the valid name or number of a language as provided by |
| 256 | the Date::Calc(3) module if given. |
| 257 | |
| 258 | This argument determines which language shall be used |
| 259 | when reading the profile, since the profile may contain |
| 260 | names of months and weekdays in its formulas in that |
| 261 | language. |
| 262 | |
| 263 | The default is English if none is specified. |
| 264 | |
| 265 | =item * |
| 266 | |
| 267 | C<$year-E<gt>init( 2002, $Profiles-E<gt>{'DE-SN'} [,LANG] );> |
| 268 | |
| 269 | This method is called by the "new()" constructor method, |
| 270 | internally, and has the same arguments as the latter. |
| 271 | |
| 272 | See immediately above for a description of these arguments. |
| 273 | |
| 274 | Note that you can also call this method explicitly yourself, |
| 275 | if needed, and you can of course subclass the Date::Calendar::Year |
| 276 | class and override the "init()" method with an method of your own. |
| 277 | |
| 278 | The holiday scheme or "profile" (i.e., the reference of |
| 279 | a hash passed as the second argument to this method) must |
| 280 | obey the following semantics and syntax: |
| 281 | |
| 282 | The keys are the names of the holiday or commemorative day |
| 283 | in question. Keys must be unique (but see further below). |
| 284 | |
| 285 | The difference between a holiday and a commemorative day is |
| 286 | that you (usually) get a day off on a holiday, whereas on a |
| 287 | purely commemorative day, you don't. |
| 288 | |
| 289 | A commemorative day is just a date with a name, nothing more. |
| 290 | |
| 291 | The values belonging to these keys can either be the code |
| 292 | reference of a callback function (see L<Date::Calendar::Profiles(3)> |
| 293 | for more details and examples), or a string. |
| 294 | |
| 295 | All other values cause a fatal error with program abortion. |
| 296 | |
| 297 | The strings can specify three types of dates: |
| 298 | |
| 299 | - fixed dates |
| 300 | (like New Year, or first of January), |
| 301 | |
| 302 | - dates relative to Easter Sunday |
| 303 | (like Ascension = Easter Sunday + 39 days), and |
| 304 | |
| 305 | - the 1st, 2nd, 3rd, 4th or last |
| 306 | of a given day of week in a given month |
| 307 | (like "the 4th Thursday of November", or Thanksgiving). |
| 308 | |
| 309 | All other types of dates must be specified via callback |
| 310 | functions. |
| 311 | |
| 312 | Note that the "last" of a given day of week is written as |
| 313 | the "5th", because the last is always either the 5th or the |
| 314 | 4th of the given day of week. So the "init()" module first |
| 315 | calculates the 5th of the requested day of week, and if that |
| 316 | doesn't exist, takes the 4th instead. |
| 317 | |
| 318 | There are also two modifier characters which may prefix the |
| 319 | string with the date formula, "#" and ":". |
| 320 | |
| 321 | The character "#" (mnemonic: it's only a comment) signals |
| 322 | that the date in question is a purely commemorative day, |
| 323 | i.e., it will not enter into any date calculations, but |
| 324 | can be queried with the "labels()" and "search()" methods, |
| 325 | and appears when printing a calendar, for instance. |
| 326 | |
| 327 | The character ":" (mnemonic: divided into two halfs) specifies |
| 328 | that the date in question is only a "half" holiday, i.e., you |
| 329 | only get half a day off instead of a full day. Some companies |
| 330 | have this sort of thing. C<:-)> |
| 331 | |
| 332 | The exact syntax for the date formula strings is the following |
| 333 | (by example): |
| 334 | |
| 335 | - Fixed dates: |
| 336 | |
| 337 | "Christmas" => "24.12", # European format (day, month) |
| 338 | "Christmas" => "24.12.", |
| 339 | |
| 340 | "Christmas" => "24Dec", |
| 341 | "Christmas" => "24.Dec", |
| 342 | "Christmas" => "24Dec.", |
| 343 | "Christmas" => "24.Dec.", |
| 344 | |
| 345 | "Christmas" => "24-12", |
| 346 | "Christmas" => "24-12-", |
| 347 | |
| 348 | "Christmas" => "24-Dec", |
| 349 | "Christmas" => "24-Dec-", |
| 350 | |
| 351 | "Christmas" => "12/25", # American format (month, day) |
| 352 | "Christmas" => "Dec25", |
| 353 | "Christmas" => "Dec/25", |
| 354 | |
| 355 | - Dates relative to Easter Sunday: |
| 356 | |
| 357 | "Ladies' Carnival" => "-52", |
| 358 | "Carnival Monday" => "-48", |
| 359 | "Mardi Gras" => "-47", |
| 360 | "Ash Wednesday" => "-46", |
| 361 | "Palm Sunday" => "-7", |
| 362 | "Maundy Thursday" => "-3", |
| 363 | "Good Friday" => "-2", |
| 364 | "Easter Sunday" => "+0", |
| 365 | "Easter Monday" => "+1", |
| 366 | "Ascension" => "+39", |
| 367 | "Whitsunday" => "+49", |
| 368 | "Whitmonday" => "+50", |
| 369 | "Corpus Christi" => "+60", |
| 370 | |
| 371 | - The 1st, 2nd, 3rd, 4th or last day of week: |
| 372 | |
| 373 | "Thanksgiving" => "4Thu11", |
| 374 | "Thanksgiving" => "4/Thu/Nov", |
| 375 | "Columbus Day" => "2/Mon/Oct", |
| 376 | "Columbus Day" => "2/Mon/10", |
| 377 | "Columbus Day" => "2/1/Oct", |
| 378 | "Columbus Day" => "2/1/10", |
| 379 | "Memorial Day" => "5/Mon/May", # LAST Monday of May |
| 380 | |
| 381 | Remember that each of these date formula strings may |
| 382 | also be prefixed with either "#" or ":": |
| 383 | |
| 384 | "Christmas" => ":24.12.", # only half a day off |
| 385 | "Valentine's Day" => "#Feb/14", # not an official holiday |
| 386 | |
| 387 | Note that the name of the month or day of week may have any |
| 388 | length you like, it just must specify the intended month or |
| 389 | day of week unambiguously. So "D", "De", "Dec", "Dece", |
| 390 | "Decem", "Decemb", "Decembe" and "December" would all |
| 391 | be valid, for example. Note also that case is ignored. |
| 392 | |
| 393 | When specifying day and month numbers, or offsets relative |
| 394 | to Easter Sunday, leading zeros are permitted (for nicely |
| 395 | indented formatting, for instance) but ignored. |
| 396 | |
| 397 | Leading zeros are not permitted in front of the ordinal |
| 398 | number [1..5] or the number of the day of week [1..7] |
| 399 | when specifying the nth day of week in a month. |
| 400 | |
| 401 | B<BEWARE> that if keys are not unique in the source code, |
| 402 | later entries will overwrite previous ones! I.e., |
| 403 | |
| 404 | ... |
| 405 | "My special holiday" => "01-11", |
| 406 | "My special holiday" => "02-11", |
| 407 | ... |
| 408 | |
| 409 | will B<NOT> set two holidays of the same name, one on November |
| 410 | first, the other on November second, but only one, on November |
| 411 | second! |
| 412 | |
| 413 | Therefore, in order to use sets of defaults and to be able |
| 414 | to override some of them, you must B<FIRST> include any hash |
| 415 | containing the default definitions, and B<THEN> write down |
| 416 | your own definitions (see also the Date::Calendar::Profiles |
| 417 | module for examples of this!), like this: |
| 418 | |
| 419 | $defaults = |
| 420 | { |
| 421 | "Holiday #1" => "01-01", |
| 422 | "Holiday #2" => "02-02", |
| 423 | "Holiday #3" => "03-03" |
| 424 | }; |
| 425 | |
| 426 | $variant1 = |
| 427 | { |
| 428 | %$defaults, |
| 429 | "Holiday #2" => "09-02", |
| 430 | "Holiday #4" => "04-04" |
| 431 | }; |
| 432 | |
| 433 | This is because of the way hashes work in Perl. |
| 434 | |
| 435 | The "init()" method proceeds as follows: |
| 436 | |
| 437 | First it checks whether the given year number lies in |
| 438 | the range [1583..2299]. A fatal error occurs if not. |
| 439 | |
| 440 | Then it determines the number of days in the requested |
| 441 | year, and stores it in the given Date::Calendar::Year |
| 442 | object. |
| 443 | |
| 444 | It then calls the Bit::Vector(3) module to allocate three |
| 445 | bit vectors with a number of bits equal to the number of |
| 446 | days in the requested year, and stores the three object |
| 447 | references (of the bit vectors) in the Date::Calendar::Year |
| 448 | object. |
| 449 | |
| 450 | (See also the description of the three methods "vec_full()", |
| 451 | "vec_half()" and "vec_full()" immediately below.) |
| 452 | |
| 453 | It then sets the bits which correspond to Saturdays and |
| 454 | Sundays in the "full holidays" bit vector. |
| 455 | |
| 456 | At last, it iterates over the keys of the given holiday |
| 457 | scheme (of the hash referred to by the hash reference |
| 458 | passed to the "init()" method as the second argument), |
| 459 | evaluates the formula (or calls the given callback |
| 460 | function), and sets the corresponding bit in the "full" |
| 461 | or "half" holidays bit vector if the calculated date |
| 462 | is valid. |
| 463 | |
| 464 | A fatal error occurs if the date formula cannot be parsed |
| 465 | or if the date returned by a formula or callback function |
| 466 | is invalid (e.g. 30-Feb-2001 or the like) or lies outside |
| 467 | the given year (e.g. Easter+365). |
| 468 | |
| 469 | Finally, the "init()" method makes sure that days marked |
| 470 | as "full" holidays do not appear as "half" holidays as |
| 471 | well. |
| 472 | |
| 473 | Then the "init()" method returns. |
| 474 | |
| 475 | Note that when deciphering the date formulas, the "init()" |
| 476 | method uses the functions "Decode_Day_of_Week()" and |
| 477 | "Decode_Month()" from the Date::Calc(3) module, which |
| 478 | are language-dependent. |
| 479 | |
| 480 | Therefore the "init()" method allows you to pass it an optional |
| 481 | third argument, which must consist of the valid name or number |
| 482 | of a language as provided by the Date::Calc(3) module. |
| 483 | |
| 484 | For the time of scanning the given holiday scheme, the "init()" |
| 485 | method will temporarily set the language to the value specified, |
| 486 | and it will restore the original value before returning. |
| 487 | |
| 488 | The default is English if none is specified. |
| 489 | |
| 490 | This means that you can provide the names of months and days of |
| 491 | week in your holiday profile in any of the languages supported |
| 492 | by the Date::Calc(3) module, provided you give the "init()" |
| 493 | method a clue (the third parameter) which language to expect. |
| 494 | |
| 495 | =item * |
| 496 | |
| 497 | C<$vector = $year-E<gt>vec_full();> |
| 498 | |
| 499 | This method returns a reference to the bit vector in the |
| 500 | given year object which contains all "full" holidays. |
| 501 | |
| 502 | B<BEWARE> that you should B<NEVER> change the contents of this |
| 503 | bit vector unless you know B<EXACTLY> what you're doing! |
| 504 | |
| 505 | You should usually only read from this bit vector, or use it |
| 506 | as an operand in bit vector operations - but never as an |
| 507 | lvalue. |
| 508 | |
| 509 | =item * |
| 510 | |
| 511 | C<$vector = $year-E<gt>vec_half();> |
| 512 | |
| 513 | This method returns a reference to the bit vector in the |
| 514 | given year object which contains all "half" holidays. |
| 515 | |
| 516 | B<BEWARE> that you should B<NEVER> change the contents of this |
| 517 | bit vector unless you know B<EXACTLY> what you're doing! |
| 518 | |
| 519 | You should usually only read from this bit vector, or use it |
| 520 | as an operand in bit vector operations - but never as an |
| 521 | lvalue. |
| 522 | |
| 523 | =item * |
| 524 | |
| 525 | C<$vector = $year-E<gt>vec_work();> |
| 526 | |
| 527 | This method returns a reference to the "workspace" bit vector |
| 528 | in the given year object. |
| 529 | |
| 530 | Note that you cannot rely on the contents of this bit vector. |
| 531 | |
| 532 | You have to set it up yourself before performing any calculations |
| 533 | with it. |
| 534 | |
| 535 | Currently the contents of this bit vector are modified by the |
| 536 | two methods "delta_workdays()" and "add_delta_workdays()", in |
| 537 | ways which are hard to predict. |
| 538 | |
| 539 | The size of this bit vector can be determined through either |
| 540 | "C<$days = $vector-E<gt>Size();>" or |
| 541 | "C<$days = $year-E<gt>val_days();>". |
| 542 | |
| 543 | =item * |
| 544 | |
| 545 | C<$size = $year-E<gt>val_days();> |
| 546 | |
| 547 | This method returns the number of days in the given year object, |
| 548 | i.e., either 365 or 366. This is also the size (number of bits) |
| 549 | of the three bit vectors contained in the given year object. |
| 550 | |
| 551 | =item * |
| 552 | |
| 553 | C<$base = $year-E<gt>val_base();> |
| 554 | |
| 555 | This method returns the value of the expression |
| 556 | "C<Date_to_Days($year-E<gt>val_year(),1,1)>", or in other words, |
| 557 | the number of days between January 1st of the year 1 and January |
| 558 | 1st of the given year, plus one. |
| 559 | |
| 560 | This value is used internally by the method "date2index()" in order |
| 561 | to calculate the "julian" date or day of the year for a given date. |
| 562 | |
| 563 | The expression above is computed only once in method "init()" and |
| 564 | then stored in one of the year object's attributes, of which this |
| 565 | method just returns the value. |
| 566 | |
| 567 | =item * |
| 568 | |
| 569 | C<$number = $year-E<gt>val_year();> |
| 570 | |
| 571 | C<$number = $year-E<gt>year();> |
| 572 | |
| 573 | These two methods are identical, the latter being a shortcut of |
| 574 | the former. |
| 575 | |
| 576 | They return the number of the year for which a calendar has been |
| 577 | stored in the given year object. |
| 578 | |
| 579 | The method name "val_year()" is used here in order to be consistent |
| 580 | with the other attribute accessor methods of this class, and the |
| 581 | method "year()" is necessary in order to be able to pass |
| 582 | Date::Calendar::Year objects as parameters instead of a year number |
| 583 | in the methods of the Date::Calendar and Date::Calendar::Year |
| 584 | modules. |
| 585 | |
| 586 | =item * |
| 587 | |
| 588 | C<@names = $year-E<gt>labels(YEAR,MONTH,DAY|DATE);> |
| 589 | |
| 590 | C<@holidays = $year-E<gt>labels();> |
| 591 | |
| 592 | C<$holidays = $year-E<gt>labels();> |
| 593 | |
| 594 | If any arguments are given, they are supposed to represent a |
| 595 | date. In that case, a list of all labels (= names of holidays) |
| 596 | associated with that date are returned. The first item returned |
| 597 | is always the name of the day of week for that date. |
| 598 | |
| 599 | If no arguments are given, the list of all available labels in |
| 600 | the given year is returned. This list does B<NOT> include any |
| 601 | names of the days of week (which would be pointless in this case). |
| 602 | |
| 603 | In list context, the resulting list itself is returned. In scalar |
| 604 | context, the number of items in the resulting list is returned. |
| 605 | |
| 606 | =item * |
| 607 | |
| 608 | C<@dates = $year-E<gt>search(PATTERN);> |
| 609 | |
| 610 | C<$dates = $year-E<gt>search(PATTERN);> |
| 611 | |
| 612 | This method searches through all the labels of the given year |
| 613 | and returns a list of date objects with all dates whose labels |
| 614 | match the given pattern. |
| 615 | |
| 616 | Note that this is a simple, case-insensitive substring search, |
| 617 | B<NOT> a full-fledged regular expression search! |
| 618 | |
| 619 | The result is guaranteed to be sorted chronologically. |
| 620 | |
| 621 | In scalar context, only the number of items in the resulting list |
| 622 | is returned, instead of the resulting list itself (as in list context). |
| 623 | |
| 624 | =item * |
| 625 | |
| 626 | C<$days = $year-E<gt>delta_workdays(YEAR,MONTH1,DAY1, YEAR,MONTH2,DAY2, FLAG1,FLAG2);> |
| 627 | |
| 628 | C<$days = $year-E<gt>delta_workdays(DATE1,DATE2,FLAG1,FLAG2);> |
| 629 | |
| 630 | This method calculates the number of work days (i.e., the number |
| 631 | of days, but excluding all holidays) between two dates. |
| 632 | |
| 633 | In other words, this method is equivalent to the "Delta_Days()" |
| 634 | function of the Date::Calc module, except that it disregards |
| 635 | holidays in its counting. |
| 636 | |
| 637 | The two flags indicate whether the start and end dates should be |
| 638 | included in the counting (that is, of course, only in case they |
| 639 | aren't holidays), or not. |
| 640 | |
| 641 | It is common, for example, that you want to know how many work |
| 642 | days are left between the current date and a given deadline. |
| 643 | |
| 644 | Typically, you will want to count the current date but not the |
| 645 | deadline's date. So you would specify "true" ("1") for FLAG1 |
| 646 | and "false" ("0") for FLAG2 in order to achieve that. |
| 647 | |
| 648 | In other words, a value of "true" means "including this date", |
| 649 | a value of "false" means "excluding this date". |
| 650 | |
| 651 | As with the "Delta_Days()" function from the Date::Calc module, |
| 652 | the dates have to be given in chronological order to yield a |
| 653 | positive result. If the dates are reversed, the result will |
| 654 | be negative. |
| 655 | |
| 656 | The parameter FLAG1 is associated with the first given date, |
| 657 | the parameter FLAG2 with the second given date (regardless |
| 658 | of whether the dates are in chronological order or not). |
| 659 | |
| 660 | An exception ("given year != object's year") is thrown if the |
| 661 | year number of either of the two given dates does not match the |
| 662 | year number associated with the given year object. |
| 663 | |
| 664 | An exception ("invalid date") is also raised if either of the |
| 665 | two date arguments does not constitute a valid date. |
| 666 | |
| 667 | =item * |
| 668 | |
| 669 | C<($date,$rest,$sign) = $year-E<gt>add_delta_workdays(YEAR,MONTH,DAY, DELTA, SIGN);> |
| 670 | |
| 671 | C<($date,$rest,$sign) = $year-E<gt>add_delta_workdays(DATE,DELTA,SIGN);> |
| 672 | |
| 673 | This method is the equivalent of the "Add_Delta_Days()" function |
| 674 | from the Date::Calc module, except that it adds work days and |
| 675 | skips holidays. |
| 676 | |
| 677 | In other words, you can add or subtract a number of work days |
| 678 | "DELTA" to/from a given date and get a new date as the result |
| 679 | (as a Date::Calc object). |
| 680 | |
| 681 | You add days (i.e., you go forward in time) with a positive |
| 682 | offset "DELTA", and you subtract days (i.e., you go backwards |
| 683 | in time) with a negative offset. |
| 684 | |
| 685 | Note that an exception ("invalid date") is raised if the |
| 686 | given date argument (the "start" date) does not constitute |
| 687 | a valid date. |
| 688 | |
| 689 | Beware that this method is limited to date calculations within |
| 690 | a single year (in contrast to the method with the same name |
| 691 | from the Date::Calendar module). |
| 692 | |
| 693 | Therefore, the method does not only return a date (object), |
| 694 | but also a "rest" and a "sign". |
| 695 | |
| 696 | The "rest" indicates how many days are still left from your |
| 697 | original DELTA after going in the desired direction and |
| 698 | reaching a year boundary. |
| 699 | |
| 700 | The "sign" indicates in which direction (future or past) one |
| 701 | needs to go in order to "eat up" the "rest" (by subtracting |
| 702 | a day from the "rest" for each work day passed), or to adjust |
| 703 | the resulting date (in order to skip any holidays directly |
| 704 | after a year boundary), if at all. |
| 705 | |
| 706 | The "sign" is -1 for going backwards in time, +1 for going |
| 707 | forward, and 0 if the result doesn't need any more fixing |
| 708 | (for instance because the result lies in the same year as |
| 709 | the starting date). |
| 710 | |
| 711 | The method "add_delta_workdays()" from the Date::Calendar |
| 712 | module uses the "rest" and "sign" return values from this |
| 713 | method in order to perform calculations which may cross |
| 714 | year boundaries. |
| 715 | |
| 716 | Therefore, it is not recommended to use this method here |
| 717 | directly, as it is rather clumsy to use, but to use the |
| 718 | method with the same name from the Date::Calendar module |
| 719 | instead, which does the same but is much easier to use |
| 720 | and moreover allows calculations which cross an arbitrary |
| 721 | number of year boundaries. |
| 722 | |
| 723 | =item * |
| 724 | |
| 725 | C<$flag = $year-E<gt>is_full(YEAR,MONTH,DAY|DATE);> |
| 726 | |
| 727 | This method returns "true" ("1") if the bit corresponding to |
| 728 | the given date is set in the bit vector representing "full" |
| 729 | holidays, and "false" ("0") otherwise. |
| 730 | |
| 731 | I.e., the method returns "true" if the given date is a (full) |
| 732 | holiday (according to the calendar profile associated with the |
| 733 | given year object). |
| 734 | |
| 735 | =item * |
| 736 | |
| 737 | C<$flag = $year-E<gt>is_half(YEAR,MONTH,DAY|DATE);> |
| 738 | |
| 739 | This method returns "true" ("1") if the bit corresponding to |
| 740 | the given date is set in the bit vector representing "half" |
| 741 | holidays, and "false" ("0") otherwise. |
| 742 | |
| 743 | I.e., the method returns "true" if the given date is a half |
| 744 | holiday (according to the calendar profile associated with the |
| 745 | given year object). |
| 746 | |
| 747 | Note that if a date is a "full" holiday, the "half" bit is |
| 748 | never set, even if you try to do so in your calendar profile, |
| 749 | on purpose or by accident. |
| 750 | |
| 751 | =item * |
| 752 | |
| 753 | C<$flag = $year-E<gt>is_work(YEAR,MONTH,DAY|DATE);> |
| 754 | |
| 755 | This method returns "true" ("1") if the bit corresponding to |
| 756 | the given date is set in the bit vector used to perform all |
| 757 | sorts of calculations, and "false" ("0") otherwise. |
| 758 | |
| 759 | B<BEWARE> that the "work" in this method's name does B<NOT> |
| 760 | come from "work days"! |
| 761 | |
| 762 | It comes from the fact that the corresponding bit vector can |
| 763 | be used for any "work" that you need to do. In other words, |
| 764 | it's a "work space". |
| 765 | |
| 766 | Therefore, this bit vector might contain about everything you |
| 767 | could imagine - including a bit pattern which marks all "work |
| 768 | days" with set bits, if it so happens! |
| 769 | |
| 770 | But you better don't rely on it, unless you put the bit pattern |
| 771 | there yourself in the first place. |
| 772 | |
| 773 | Note that you can get a reference to this bit vector (in order |
| 774 | to fill it with any bit pattern you like) using the method |
| 775 | "vec_work()", described further above in this document. |
| 776 | |
| 777 | The number of bits in this bit vector is the same as the number |
| 778 | of days in the given year "C<$year>", which you can retrieve |
| 779 | through either "C<$days = $year-E<gt>vec_work-E<gt>Size();>" |
| 780 | or "C<$days = $year-E<gt>val_days();>". |
| 781 | |
| 782 | See also L<Bit::Vector(3)> for more details. |
| 783 | |
| 784 | =back |
| 785 | |
| 786 | =head1 SEE ALSO |
| 787 | |
| 788 | Bit::Vector(3), Date::Calendar(3), Date::Calendar::Profiles(3), |
| 789 | Date::Calc::Object(3), Date::Calc(3). |
| 790 | |
| 791 | =head1 VERSION |
| 792 | |
| 793 | This man page documents "Date::Calendar::Year" version 5.3. |
| 794 | |
| 795 | =head1 AUTHOR |
| 796 | |
| 797 | Steffen Beyer |
| 798 | mailto:sb@engelschall.com |
| 799 | http://www.engelschall.com/u/sb/download/ |
| 800 | |
| 801 | =head1 COPYRIGHT |
| 802 | |
| 803 | Copyright (c) 2000 - 2002 by Steffen Beyer. All rights reserved. |
| 804 | |
| 805 | =head1 LICENSE |
| 806 | |
| 807 | This package is free software; you can redistribute it and/or |
| 808 | modify it under the same terms as Perl itself, i.e., under the |
| 809 | terms of the "Artistic License" or the "GNU General Public License". |
| 810 | |
| 811 | Please refer to the files "Artistic.txt" and "GNU_GPL.txt" |
| 812 | in this distribution for details! |
| 813 | |
| 814 | =head1 DISCLAIMER |
| 815 | |
| 816 | This package is distributed in the hope that it will be useful, |
| 817 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 818 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 819 | |
| 820 | See the "GNU General Public License" for more details. |
| 821 | |