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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605
use std::convert::{TryFrom, TryInto}; use smallvec::*; use crate::convert::year::backend::{CHALAKIM_BETWEEN_MOLAD, FIRST_MOLAD}; use crate::convert::*; use crate::holidays::get_chol_list; use crate::holidays::get_shabbos_list; use crate::holidays::get_special_parsha_list; use crate::holidays::get_yt_list; use chrono::{Duration, Utc}; use std::num::NonZeroI8; pub(crate) mod backend; use crate::convert::year::backend::{ get_rosh_hashana, months_per_year, return_year_sched, CHALAKIM_PER_HOUR, EPOCH, FIRST_YEAR, YEAR_SCHED, }; use crate::prelude::HebrewMonth::{Adar, Adar1, Adar2}; use crate::prelude::{ConversionError, HebrewMonth, Molad}; /// HebrewYear holds data on a given year. It's faster to get multiple HebrewDates from /// an existing HebrewYear rather than generating each one on its own. #[derive(Copy, Clone, Debug)] pub struct HebrewYear { pub(crate) year: u64, pub(crate) day_of_rh: Day, pub(crate) day_of_next_rh: Day, pub(crate) months_per_year: u64, pub(crate) sched: [u8; 14], pub(crate) year_len: u64, pub(crate) days_since_epoch: u64, pub(crate) chalakim_since_epoch: u64, } impl HebrewYear { #[inline] pub fn new(year: u64) -> Result<HebrewYear, ConversionError> { //! Returns a new HebrewYear on success or a ConversionError on failure. //! //! # Arguments //! //! `year` - The Hebrew year //! if year < FIRST_YEAR + 1 { Err(ConversionError::YearTooSmall) } else { let cur_rh = get_rosh_hashana(year); let next_rh = get_rosh_hashana(year + 1); let days_since_epoch = cur_rh.0; let chalakim_since_epoch = cur_rh.2; let year_len = next_rh.0 - cur_rh.0; let months_per_year = months_per_year(year); let sched = &YEAR_SCHED[return_year_sched(year_len)]; Ok(HebrewYear { day_of_rh: get_rosh_hashana(year).1, year, day_of_next_rh: get_rosh_hashana(year + 1).1, months_per_year, sched: sched.clone(), days_since_epoch, year_len, chalakim_since_epoch, }) } } #[inline] /// Returns if this year is a leap year. /// /// ``` /// use heca_lib::prelude::*; /// use heca_lib::HebrewYear; /// assert_eq!(HebrewYear::new(5779)?.is_leap_year(),true); /// # Ok::<(),ConversionError>(()) /// ``` pub fn is_leap_year(&self) -> bool { self.months_per_year == 13 } #[inline] /// Returns the type of year. /// /// A Hebrew year can be one of 14 combinations of length and starting day. /// /// # Returns /// /// A [MonthSchedule](../heca_lib/prelude/enum.MonthSchedule.html) pub fn year_type(&self) -> MonthSchedule { if self.months_per_year == 12 { match self.day_of_rh { Day::Monday => { if self.sched[1] == 30 && self.sched[2] == 30 { MonthSchedule::BaShaH } else if self.sched[1] == 29 && self.sched[2] == 29 { MonthSchedule::BaChaG } else { panic!(format!( "Year {} is 12 months, stars on Monday, yet has Cheshvan {} days and Kislev {} days", self.year, self.sched[1], self.sched[2] )) } } Day::Tuesday => { if self.sched[1] == 29 && self.sched[2] == 30 { MonthSchedule::GaChaH } else { panic!(format!( "Year {} is 12 months, starts on Tuesday, yet has Cheshvan {} days and Kislev {} days", self.year, self.sched[1], self.sched[2] )) } } Day::Thursday => { if self.sched[1] == 29 && self.sched[2] == 30 { MonthSchedule::HaKaZ } else if self.sched[1] == 30 && self.sched[2] == 30 { MonthSchedule::HaShA } else { panic!(format!( "Year {} is 12 months, starts on Thursday, yet has Cheshvan {} days and Kislev {} days", self.year, self.sched[1], self.sched[2] )) } } Day::Shabbos => { if self.sched[1] == 30 && self.sched[2] == 30 { MonthSchedule::ZaShaG } else if self.sched[1] == 29 && self.sched[2] == 29 { MonthSchedule::ZaChA } else { panic!(format!( "Year {} is 12 months, stars on Shabbos, yet has Cheshvan {} days and Kislev {} days", self.year, self.sched[1], self.sched[2] )) } } x => panic!(format!("Rosh Hashana should never fall out on {:?}", x)), } } else { match self.day_of_rh { Day::Monday => { if self.sched[1] == 30 && self.sched[2] == 30 { MonthSchedule::BaShaZ } else if self.sched[1] == 29 && self.sched[2] == 29 { MonthSchedule::BaChaH } else { panic!(format!( "Year {} is 13 months, stars on Monday, yet has Cheshvan {} days and Kislev {} days", self.year, self.sched[1], self.sched[2] )) } } Day::Tuesday => { if self.sched[1] == 29 && self.sched[2] == 30 { MonthSchedule::GaKaZ } else { panic!(format!( "Year {} is 13 months, starts on Tuesday, yet has Cheshvan {} days and Kislev {} days", self.year, self.sched[1], self.sched[2] )) } } Day::Thursday => { if self.sched[1] == 30 && self.sched[2] == 30 { MonthSchedule::HaShaG } else if self.sched[1] == 29 && self.sched[2] == 29 { MonthSchedule::HaChA } else { panic!(format!( "Year {} is 13 months, starts on Thursday, yet has Cheshvan {} days and Kislev {} days", self.year, self.sched[1], self.sched[2] )) } } Day::Shabbos => { if self.sched[1] == 30 && self.sched[2] == 30 { MonthSchedule::ZaShaH } else if self.sched[1] == 29 && self.sched[2] == 29 { MonthSchedule::ZaChaG } else { panic!(format!( "Year {} is 13 months, stars on Shabbos, yet has Cheshvan {} days and Kislev {} days", self.year, self.sched[1], self.sched[2] )) } } x => panic!(format!("Rosh Hashana should never fall out on {:?}", x)), } } } /// Returns the year. /// /// # Examples: /// /// ``` /// use std::num::NonZeroI8; /// use heca_lib::prelude::*; /// use heca_lib::{HebrewDate, HebrewYear}; /// let year = HebrewYear::new(5779)?; /// assert_eq!(year.year(), 5779); /// # Ok::<(),ConversionError>(()) /// ``` #[inline] pub fn year(&self) -> u64 { self.year } /// Returns a HebrewDate from the current year and a supplied month and day. /// /// # Arguments: /// /// `month` - The Hebrew month. /// /// `day` - The day of the Hebrew month. /// /// # Examples: /// /// ``` /// use std::num::NonZeroI8; /// use heca_lib::prelude::*; /// use heca_lib::{HebrewDate, HebrewYear}; /// let year = HebrewYear::new(5779)?; /// assert_eq!( /// year.get_hebrew_date(HebrewMonth::Tishrei, NonZeroI8::new(10).unwrap())?, /// HebrewDate::from_ymd(5779, HebrewMonth::Tishrei, NonZeroI8::new(10).unwrap())? /// ); /// # Ok::<(),ConversionError>(()) /// ``` /// /// # Notes: /// /// Day must be above zero. If it's below zero, the function returns TooManyDaysInMonth. In a future release, day will be a NonZeroU8 so that it will be impossible to supply a negative number. #[inline] pub fn get_hebrew_date( self, month: HebrewMonth, day: NonZeroI8, ) -> Result<HebrewDate, ConversionError> { HebrewDate::from_ymd_internal(month, day, self) } pub(crate) fn get_hebrewdate_from_days_after_rh(self, amnt_days: u64) -> HebrewDate { let mut remainder = amnt_days - self.days_since_epoch; let mut month: u64 = 0; for days_in_month in self.sched.iter() { if remainder < u64::from(*days_in_month) { break; } month += 1; remainder -= u64::from(*days_in_month); } HebrewDate { year: self, month: HebrewMonth::from(month), day: NonZeroI8::new((remainder + 1) as i8).unwrap(), } } /// Returns all the days when the Torah is read. /// /// # Arguments /// /// `location` - Specify if you're looking for the calendar in Israel or in the Diaspora. Is /// relevent as there's only one day of Yom Tov in Israel while there are two day of Yom Tov outside. /// Since we don't read the Weekly Parsha on Yom Tov, in a year when the 8th day of Pesach is on a Shabbos, /// Israelis read the next Parsha while the Diaspora reads the Yom Tov Parsha, catching up in the summer. /// /// `yt_types` - An array containing `TorahReadingType`. This should be used as a flag to /// specify which types of Torah readings you want to list. /// /// # Returns /// /// Returns an array (or a vec) of days. /// /// # Note /// /// This may unsorted, and is returned under no defined order. /// /// # Examples /// /// ``` /// use std::num::NonZeroI8; /// use heca_lib::prelude::*; /// use heca_lib::{HebrewDate, HebrewYear}; /// let year = HebrewYear::new(5779)?; /// let shabbosim = year.get_holidays(Location::Chul, &[TorahReadingType::Shabbos, TorahReadingType::SpecialParsha, TorahReadingType::Chol, TorahReadingType::YomTov]); /// let mut count = 0; /// for s in shabbosim.into_iter() { /// if s.name() == TorahReading::Shabbos(Parsha::Bereishis) { /// assert_eq!(s.day(), HebrewDate::from_ymd(5779,HebrewMonth::Tishrei, NonZeroI8::new(27).unwrap())?); /// count += 1; /// } /// else if s.name() == TorahReading::SpecialParsha(SpecialParsha::Zachor) { /// assert_eq!(s.day(), HebrewDate::from_ymd(5779,HebrewMonth::Adar2, NonZeroI8::new(9).unwrap())?); /// count += 1; /// } /// else if s.name() == TorahReading::Chol(Chol::Chanukah1) { /// assert_eq!(s.day(), HebrewDate::from_ymd(5779,HebrewMonth::Kislev, NonZeroI8::new(25).unwrap())?); /// count += 1; /// } /// else if s.name() == TorahReading::YomTov(YomTov::Shavuos1) { /// assert_eq!(s.day(), HebrewDate::from_ymd(5779,HebrewMonth::Sivan, NonZeroI8::new(6).unwrap())?); /// count += 1; /// } /// } /// assert_eq!(count,4); /// # Ok::<(),ConversionError>(()) /// ``` pub fn get_holidays( &self, location: Location, yt_types: &[TorahReadingType], ) -> SmallVec<[TorahReadingDay; 256]> { let mut return_vec: SmallVec<[TorahReadingDay; 256]> = SmallVec::new(); if yt_types.contains(&TorahReadingType::YomTov) { return_vec.extend_from_slice(&get_yt_list(self.clone(), location)); } if yt_types.contains(&TorahReadingType::Chol) { return_vec.extend_from_slice(&get_chol_list(self.clone())); } if yt_types.contains(&TorahReadingType::Shabbos) { return_vec.extend_from_slice(&get_shabbos_list(self.clone(), location)); } if yt_types.contains(&TorahReadingType::SpecialParsha) { return_vec.extend_from_slice(&get_special_parsha_list(self.clone())); } return_vec } /// Returns the Molad of a given month, or a ConversionError if trying to get Molad of a month which is does not exist in that year. /// /// # Note: /// The Molad has no modern Halachic significance since Rosh Chodesh isn't derived from the Molad. However, it is useful to know as some say that one should know the Molad during the Birkas HaChodesh. pub fn get_molad(&self, month: HebrewMonth) -> Result<Molad, ConversionError> { let chalakim_since_epoch = if self.is_leap_year() { match month { HebrewMonth::Tishrei => 0, HebrewMonth::Cheshvan => 1, HebrewMonth::Kislev => 2, HebrewMonth::Teves => 3, HebrewMonth::Shvat => 4, Adar1 => 5, Adar2 => 6, HebrewMonth::Nissan => 7, HebrewMonth::Iyar => 8, HebrewMonth::Sivan => 9, HebrewMonth::Tammuz => 10, HebrewMonth::Av => 11, HebrewMonth::Elul => 12, Adar => { return Err(ConversionError::IsLeapYear); } } } else { match month { HebrewMonth::Tishrei => 0, HebrewMonth::Cheshvan => 1, HebrewMonth::Kislev => 2, HebrewMonth::Teves => 3, HebrewMonth::Shvat => 4, HebrewMonth::Adar => 5, HebrewMonth::Nissan => 6, HebrewMonth::Iyar => 7, HebrewMonth::Sivan => 8, HebrewMonth::Tammuz => 9, HebrewMonth::Av => 10, HebrewMonth::Elul => 11, Adar1 => return Err(ConversionError::IsNotLeapYear), Adar2 => return Err(ConversionError::IsNotLeapYear), } } * CHALAKIM_BETWEEN_MOLAD + self.chalakim_since_epoch + FIRST_MOLAD; let minutes_since_epoch = (chalakim_since_epoch / (CHALAKIM_PER_HOUR / 60)) .try_into() .unwrap(); let remainder = (chalakim_since_epoch % (CHALAKIM_PER_HOUR / 60)) .try_into() .unwrap(); let day = EPOCH.clone() + Duration::minutes(minutes_since_epoch); Ok(Molad { day, remainder }) } } #[test] fn test_get_molad() { use chrono::prelude::*; let hebrew_year = HebrewYear::new(5780).unwrap(); let p = hebrew_year.get_molad(HebrewMonth::Tishrei).unwrap(); assert_eq!( p, Molad { day: Utc.ymd(2019, 9, 29).and_hms(5, 50, 0), remainder: 5 } ); let p = hebrew_year.get_molad(HebrewMonth::Cheshvan).unwrap(); assert_eq!( p, Molad { day: Utc.ymd(2019, 10, 28).and_hms(18, 34, 0), remainder: 6 } ); let hebrew_year = HebrewYear::new(5781).unwrap(); let p = hebrew_year.get_molad(HebrewMonth::Elul).unwrap(); assert_eq!( p, Molad { day: Utc.ymd(2021, 8, 8).and_hms(10, 43, 0), remainder: 10 } ); //check error let hebrew_year = HebrewYear::new(5780).unwrap(); assert_eq!( hebrew_year.get_molad(HebrewMonth::Adar1), Err(ConversionError::IsNotLeapYear) ); let hebrew_year = HebrewYear::new(5779).unwrap(); assert_eq!( hebrew_year.get_molad(HebrewMonth::Adar), Err(ConversionError::IsLeapYear) ); } /// Returns a HebrewDate on success, or a ConversionError on failure. /// /// # Arguments /// * `date` - The Gregorian date. /// /// # Note: /// Hebrew days start at sundown, not midnight, so there isn't a full 1:1 mapping between /// Gregorian days and Hebrew. So when you look up the date of Rosh Hashana 5779, most calendars will say that it's on Monday the 10th of September, 2018, while Rosh Hashana really started at sundown on the 9th of September. /// /// I'm trying to be a _bit_ more precise, so I made the date cutoff at 6:00 PM. So for example: /// /// ``` /// use std::num::NonZeroI8; /// use std::convert::TryInto; /// /// use chrono::Utc; /// use chrono::offset::TimeZone; /// use heca_lib::prelude::*; /// use heca_lib::HebrewDate; /// /// let hebrew_date: HebrewDate = Utc.ymd(2018,9,10).and_hms(17,59,59).try_into()?; /// assert_eq!(hebrew_date,HebrewDate::from_ymd(5779,HebrewMonth::Tishrei,NonZeroI8::new(1).unwrap())?); /// # Ok::<(),ConversionError>(()) /// ``` /// /// while /// /// ``` /// use std::num::NonZeroI8; /// use std::convert::TryInto; /// /// use chrono::Utc; /// use chrono::offset::TimeZone; /// use heca_lib::prelude::*; /// use heca_lib::HebrewDate; /// /// /// let hebrew_date: HebrewDate = Utc.ymd(2018,9,10).and_hms(18,0,0).try_into()?; /// assert_eq!(hebrew_date, HebrewDate::from_ymd(5779,HebrewMonth::Tishrei,NonZeroI8::new(2).unwrap())?); /// # Ok::<(),ConversionError>(()) /// ``` /// # Error Values: /// * YearTooSmall - This algorithm won't work if the year is before year 4. /// impl TryFrom<DateTime<Utc>> for HebrewDate { type Error = ConversionError; fn try_from(original_day: DateTime<Utc>) -> Result<HebrewDate, ConversionError> { HebrewDate::from_gregorian(original_day) } } /// Gets the Gregorian date for the current Hebrew date. /// /// # Notes /// /// This function returns the DateTime of the given HebrewDate at nightfall. /// /// For example, Yom Kippur 5779 started at sunset of September 18, 2018. So /// ``` /// use std::num::NonZeroI8; /// /// use chrono::prelude::*; /// use heca_lib::prelude::*; /// use heca_lib::HebrewDate; /// /// let gregorian_date: DateTime<Utc> = HebrewDate::from_ymd(5779,HebrewMonth::Tishrei,NonZeroI8::new(10).unwrap())?.into(); /// assert_eq!(gregorian_date ,Utc.ymd(2018, 9,18).and_hms(18,00,00)); /// # Ok::<(),ConversionError>(()) /// ``` /// ## Algorithm: /// The conversion is done (at the moment) according to the calculation of the Rambam (Maimonidies), as is documented in [Hilchos Kiddush Ha'chodesh](https://www.sefaria.org/Mishneh_Torah%2C_Sanctification_of_the_New_Month.6.1?lang=bi&with=all&lang2=en). /// /// The algorithm is as follows: /// /// 1. There are exactly 1080 Chalakim (parts) in an hour. /// 2. There are exactly (well, not really. But it's close enough that we use that number as exact.) 29 days, 12 hours, and 793 Chalakim between new moons. /// /// So that's the basic numbers. Regarding the calendar itself: /// /// 3. All months are either 29 or 30 days long. /// 4. There are either 12 or 13 months in the Hebrew calendar, depending if it's a leap year. When it's a leap year, Adar (which generally is in the late winter or early spring) is doubled into a "first Adar" (Adar1) and a "second Adar" (Adar2). /// 5. There is a 19 year cycle of leap years. So the first two years of the cycle are regular years, the one after that's a leap year. Then another two are regular, then a leap year. Then it's regular, leap, regular, regular, leap, regular, regular, leap. /// 6. Year 3763 was the first year of its 19 year cycle. /// 7. Now you can calculate when's the New Moon before a given Rosh Hashana. /// /// So how to calculate Rosh Hashana: /// /// 8. If the New Moon is in the afternoon, Rosh Hashana is postponed to the next day. /// 9. If Rosh Hashana's starting on a Sunday (Saturday night), Wednesday (Tuesday night), or Friday (Thursday night) - postpone it by a day. /// /// If any of the above two conditions were fulfilled. Good. You just found Rosh Hashana. If not: /// /// 10. If the New Moon is on a Tuesday after 3am+204 Chalakim and the coming year is not a leap year, Rosh Hashana is postponed to that upcoming Thursday instead. /// 11. If the New Moon is on a Monday after 9am+589 Chalakim, and the previous year was a leap year, then Rosh Hashana is postponed to Tuesday. /// /// /// Now you have all the Rosh Hashanas. /// /// 12. In general, months alternate between “Full” (30 days long) and “Empty” (29 days long) months. So Tishrei is full, Teves is empty, Shvat is full, Adar is empty, Nissan is full. /// 13. When the year is a leap year, Adar 1 is full and Adar 2 is empty. (So a full Shvat is followed by a full Adar1). /// /// Knowing this, you can calculate any other date of the year. /// /// But wait! We're playing with the date when Rosh Hashana will start, so not every year will be the same length! How do we make up these days? /// /// So there's a last little bit: /// /// 14. Cheshvan and Kislev are variable length months – some years both are full, some years both are empty, and some years Cheshvan is full and Kislev is empty - depending on the day Rosh Hashana starts (and the day _the next Rosh Hashana starts_) and how many days are in the year. impl From<HebrewDate> for DateTime<Utc> { fn from(h: HebrewDate) -> Self { h.to_gregorian() } } mod test { #[test] fn make_new_year() { use super::*; for i in 4000..5000 { println!("{}", i); HebrewYear::new(i).unwrap(); } } #[test] fn check_year_type() { use super::*; use chrono::prelude::*; for i in 3765..9999 { println!("{}", i); let y = HebrewYear::new(i).unwrap(); let t = y.year_type(); match t { MonthSchedule::GaChaH | MonthSchedule::BaShaH | MonthSchedule::BaChaH | MonthSchedule::ZaShaH => assert_eq!( y.get_hebrew_date(HebrewMonth::Nissan, NonZeroI8::new(16).unwrap()) .unwrap() .to_gregorian() .weekday(), Weekday::Thu ), MonthSchedule::HaShaG | MonthSchedule::ZaShaG | MonthSchedule::ZaChaG | MonthSchedule::BaChaG => assert_eq!( y.get_hebrew_date(HebrewMonth::Nissan, NonZeroI8::new(16).unwrap()) .unwrap() .to_gregorian() .weekday(), Weekday::Tue ), MonthSchedule::HaShA | MonthSchedule::ZaChA | MonthSchedule::HaChA => assert_eq!( y.get_hebrew_date(HebrewMonth::Nissan, NonZeroI8::new(16).unwrap()) .unwrap() .to_gregorian() .weekday(), Weekday::Sun ), MonthSchedule::HaKaZ | MonthSchedule::BaShaZ | MonthSchedule::GaKaZ => assert_eq!( y.get_hebrew_date(HebrewMonth::Nissan, NonZeroI8::new(16).unwrap()) .unwrap() .to_gregorian() .weekday(), Weekday::Sat ), } } } }