Class: HebrewDate

Inherits:
Delegator
  • Object
show all
Extended by:
HebrewDateSupport::HolidayMethods::ClassMethods
Includes:
Comparable, HebrewDateSupport::HolidayMethods, HebrewDateSupport::ParshaMethods
Defined in:
lib/hebrew_date.rb

Overview

A class that represents a date in both the Gregorian and Hebrew calendars simultaneously. Note that you may call any Date methods on this class and it should respond accordingly.

Constant Summary collapse

HEBREW_EPOCH = 
-1373429
HEBREW_MONTH_NAMES = 
['Nissan', 'Iyar', 'Sivan', 'Tammuz', 'Av', 'Elul',
'Tishrei', 'Cheshvan', 'Kislev', 'Teves', 'Shvat',
'Adar', 'Adar II']

Constants included from HebrewDateSupport::HolidayMethods::ClassMethods

HebrewDateSupport::HolidayMethods::ClassMethods::HOLIDAYS

Constants included from HebrewDateSupport::ParshaMethods

HebrewDateSupport::ParshaMethods::MON_LONG, HebrewDateSupport::ParshaMethods::MON_LONG_LEAP, HebrewDateSupport::ParshaMethods::MON_LONG_LEAP_ISRAEL, HebrewDateSupport::ParshaMethods::MON_SHORT, HebrewDateSupport::ParshaMethods::MON_SHORT_LEAP, HebrewDateSupport::ParshaMethods::MON_SHORT_LEAP_ISRAEL, HebrewDateSupport::ParshaMethods::PARSHA_NAMES, HebrewDateSupport::ParshaMethods::SAT_LONG, HebrewDateSupport::ParshaMethods::SAT_LONG_LEAP, HebrewDateSupport::ParshaMethods::SAT_SHORT, HebrewDateSupport::ParshaMethods::SAT_SHORT_LEAP, HebrewDateSupport::ParshaMethods::THU_LONG, HebrewDateSupport::ParshaMethods::THU_LONG_LEAP, HebrewDateSupport::ParshaMethods::THU_NORMAL, HebrewDateSupport::ParshaMethods::THU_NORMAL_ISRAEL, HebrewDateSupport::ParshaMethods::THU_SHORT_LEAP

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from HebrewDateSupport::HolidayMethods::ClassMethods

from_holiday

Methods included from HebrewDateSupport::HolidayMethods

#candle_lighting_day?, #first_day_yom_tov?, #havdala_day?, #holiday, #omer, #omer_to_s, #rosh_chodesh?, #second_day_yom_tov?

Methods included from HebrewDateSupport::ParshaMethods

#parsha

Constructor Details

#initialize(year_or_date_object = nil, month = nil, date = nil) ⇒ HebrewDate

Returns a new instance of HebrewDate.



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# File 'lib/hebrew_date.rb', line 67

def initialize(year_or_date_object=nil, month=nil, date=nil)
  @abs_date = 0
  skip_hebrew_date = false
  if year_or_date_object === true
    skip_hebrew_date = true
    year_or_date_object = nil
  end

  if month && date
    @year = year_or_date_object
    @month = month
    @date = date
  else
    date = year_or_date_object || Date.today
    @year = date.year
    @month = date.month
    @date = date.mday
  end
  @israeli = self.class.israeli
  @ashkenaz = self.class.ashkenaz
  @debug = self.class.debug
  set_date(@year, @month, @date) unless skip_hebrew_date
  super(Date.new)
end

Class Attribute Details

.ashkenaz ⇒ Boolean

Returns Whether to use Ashkenazi pronunciation.

Returns:

  • (Boolean) —

    Whether to use Ashkenazi pronunciation.



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# File 'lib/hebrew_date.rb', line 32

def ashkenaz
  @ashkenaz
end

.debug ⇒ Object 



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# File 'lib/hebrew_date.rb', line 42

def debug
  @debug
end

.israeli ⇒ Boolean

Returns Whether to use Israeli parsha/holiday scheme.

Returns:

  • (Boolean) —

    Whether to use Israeli parsha/holiday scheme.



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# File 'lib/hebrew_date.rb', line 35

def israeli
  @israeli
end

.replace_saturday ⇒ Boolean

Returns If true, replaces “Saturday” or “Sat” in #strftime with “Shabbat” or “Shabbos” depending on the #ashkenaz value.

Returns:

  • (Boolean) —

    If true, replaces “Saturday” or “Sat” in #strftime with “Shabbat” or “Shabbos” depending on the #ashkenaz value.



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# File 'lib/hebrew_date.rb', line 39

def replace_saturday
  @replace_saturday
end

Instance Attribute Details

#abs_date ⇒ Object (readonly) 



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# File 'lib/hebrew_date.rb', line 65

def abs_date
  @abs_date
end

#date ⇒ Integer (readonly)

Returns the current Gregorian day of the month (1-31).

Returns:

  • (Integer) —

    the current Gregorian day of the month (1-31).



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# File 'lib/hebrew_date.rb', line 53

def date
  @date
end

#hebrew_date ⇒ Integer (readonly)

Returns the current Hebrew date (1-30).

Returns:

  • (Integer) —

    the current Hebrew date (1-30).



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# File 'lib/hebrew_date.rb', line 62

def hebrew_date
  @hebrew_date
end

#hebrew_month ⇒ Integer (readonly)

Returns the current Hebrew month (1-13).

Returns:

  • (Integer) —

    the current Hebrew month (1-13).



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# File 'lib/hebrew_date.rb', line 59

def hebrew_month
  @hebrew_month
end

#hebrew_year ⇒ Integer (readonly)

Returns the current Hebrew year (e.g. 5775).

Returns:

  • (Integer) —

    the current Hebrew year (e.g. 5775).



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# File 'lib/hebrew_date.rb', line 56

def hebrew_year
  @hebrew_year
end

#month ⇒ Integer (readonly)

Returns the current Gregorian month (1-12).

Returns:

  • (Integer) —

    the current Gregorian month (1-12).



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# File 'lib/hebrew_date.rb', line 50

def month
  @month
end

#year ⇒ Integer (readonly)

Returns the current Gregorian year (e.g. 2008).

Returns:

  • (Integer) —

    the current Gregorian year (e.g. 2008).



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# File 'lib/hebrew_date.rb', line 47

def year
  @year
end

Class Method Details

.day_name(day) ⇒ String

Get the name of the given day (1-7).

Parameters:

  • day (Integer)

Returns:

  • (String) 


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# File 'lib/hebrew_date.rb', line 473

def day_name(day)
  if self.replace_saturday && day == 7
    self.ashkenaz ? 'Shabbos' : 'Shabbat'
  else
    Date::DAYNAMES[day - 1]
  end
end

.hebrew_leap_year?(year) ⇒ Boolean

Is this a Hebrew leap year?

Parameters:

  • year (Integer) —

    the Hebrew year.

Returns:

  • (Boolean) 


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# File 'lib/hebrew_date.rb', line 459

def hebrew_leap_year?(year)
  (((7 * year) + 1).remainder(19)) < 7
end

.hebrew_month_to_s(month, year = nil) ⇒ String

Get the name of the given Hebrew month.

Parameters:

  • month (Integer)
  • year (Integer) (defaults to: nil)

Returns:

  • (String) 


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# File 'lib/hebrew_date.rb', line 363

def self.hebrew_month_to_s(month, year=nil)
  year ||= self.new.hebrew_year
  if hebrew_leap_year?(year) && month == 12
    'Adar I'
  else
    name = HEBREW_MONTH_NAMES[month - 1]
    if name == 'Teves' && !self.ashkenaz
      name = 'Tevet'
    end
    name
  end
end

.last_month_of_hebrew_year(year) ⇒ Integer

The last month in the Hebrew year (12 or 13).

Parameters:

  • year (Integer) —

    the Hebrew year.

Returns:

  • (Integer) 


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# File 'lib/hebrew_date.rb', line 466

def last_month_of_hebrew_year(year)
  hebrew_leap_year?(year) ? 13 : 12
end

.new_from_hebrew(year, month, date) ⇒ Object

Create a HebrewDate with initialized Hebrew date values.

Parameters:

  • year (Integer) —

    the Hebrew year (e.g. 5774)

  • month (Integer) —

    the Hebrew month (1-13)

  • date (Integer) —

    the day of the Hebrew month (1-30)



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# File 'lib/hebrew_date.rb', line 169

def self.new_from_hebrew(year, month, date)
  d = self.new(true)
  @year = 1
  @month = 1
  @date = 1
  d.set_hebrew_date(year, month, date, true)
  d
end

Instance Method Details

#+(other) ⇒ HebrewDate

Parameters:

  • other (Integer)

Returns:



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# File 'lib/hebrew_date.rb', line 117

def +(other)
  date = self.clone
  (1..other).each do |i|
    date.forward
  end
  date
end

#-(other) ⇒ HebrewDate

Parameters:

  • other (Integer)

Returns:



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# File 'lib/hebrew_date.rb', line 127

def -(other)
  date = self.clone
  (1..other).each do |i|
    date.back
  end
  date
end

#<=>(other) ⇒ Integer

Comparison operator.

Parameters:

Returns:

  • (Integer) —

    -1, 0, or 1



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# File 'lib/hebrew_date.rb', line 138

def <=>(other)
  self.to_date <=> other.to_date
end

#__getobj__ ⇒ Object 



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# File 'lib/hebrew_date.rb', line 106

def __getobj__
  self.to_date
end

#__setobj__(obj) ⇒ Object 



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# File 'lib/hebrew_date.rb', line 111

def __setobj__(obj)
  # do nothing
end

#back ⇒ HebrewDate

Move back one day.

Returns:

  • (HebrewDate) —

    the same HebrewDate object again, for chaining.



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# File 'lib/hebrew_date.rb', line 316

def back
  # Change Gregorian date
  if @date == 1
    if @month == 1
      @month = 12
      @year -= 1
    else
      @month -= 1
    end

    # change to last day of previous month
    @date = last_day_of_month
  else
    @date -= 1
  end

  # Change Hebrew date
  if @hebrew_date == 1
    if @hebrew_month == 1 # Nisan
      @hebrew_month = last_month_of_hebrew_year
    elsif @hebrew_month == 7 # Rosh Hashana
      @hebrew_year -= 1
      @hebrew_month -= 1
    else
      @hebrew_month -= 1
    end
    @hebrew_date = last_day_of_hebrew_month
  else
    @hebrew_date -= 1
  end

  # Change the absolute date
  @abs_date -= 1

  self
end

#day ⇒ Integer

Get the day of the week.

Returns:

  • (Integer) —

    the day of the week, 1-7.



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# File 'lib/hebrew_date.rb', line 431

def day
  to_date.strftime('%w').to_i + 1
end

#downto(min, &block) ⇒ Enumerator|self

This method is equivalent to step(min, -1){|date| …}.

Parameters:

  • min (Integer)

Returns:

  • (Enumerator|self) 


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# File 'lib/hebrew_date.rb', line 152

def downto(min, &block)
  return to_enum(:downto, min) unless block_given?
  self.step(min, -1, &block)
end

#forward ⇒ HebrewDate

Move forward one day.

Returns:

  • (HebrewDate) —

    the same HebrewDate object again, for chaining.



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# File 'lib/hebrew_date.rb', line 245

def forward
  # Change Gregorian date
  if @date == last_day_of_month
    if @month == 12
      # last day of year
      @year += 1
      @month = 1
      @date = 1
    else
      @month += 1
      @date = 1
    end
  else
    # if not last day of month
    @date += 1
  end

  # Change Hebrew date
  if @hebrew_date == last_day_of_hebrew_month
    if @hebrew_month == 6
      # last day of Elul (i.e. last day of Hebrew year)
      @hebrew_year += 1
      @hebrew_month += 1
      @hebrew_date = 1
    elsif @hebrew_month == last_month_of_hebrew_year
      # last day of Adar or Adar II
      @hebrew_month = 1
      @hebrew_date = 1
    else
      @hebrew_month += 1
      @hebrew_date = 1
    end
  else
    # not last day of month
    @hebrew_date += 1
  end

  # increment the absolute date
  @abs_date += 1

  self
end

#hebrew_leap_year? ⇒ Boolean

Is this a Hebrew leap year?

Returns:

  • (Boolean) 


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# File 'lib/hebrew_date.rb', line 491

def hebrew_leap_year?
  self.class.hebrew_leap_year?(@hebrew_year)
end

#hebrew_month_to_s ⇒ String

Get the name of the current Hebrew month.

Returns:

  • (String) 


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# File 'lib/hebrew_date.rb', line 355

def hebrew_month_to_s
  self.class.hebrew_month_to_s(@hebrew_month, @hebrew_year)
end

#inspect ⇒ Object 



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# File 'lib/hebrew_date.rb', line 93

def inspect
  strftime('*Y-*-m-*-d (%Y-%-m-%-d)')
end

#last_day_of_hebrew_month(month = nil) ⇒ Integer

Last day of the current Hebrew month.

Parameters:

  • month (Integer) (defaults to: nil) —

    Used internally.

Returns:

  • (Integer) 


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# File 'lib/hebrew_date.rb', line 498

def last_day_of_hebrew_month(month=nil)
  month ||= @hebrew_month
  if month == 2 ||
    month == 4 ||
    month == 6 ||
    (month == 8 && !_cheshvan_long?) ||
    (month == 9 && _kislev_short?) ||
    month == 10 ||
    (month == 12 && !hebrew_leap_year?) ||
    month == 13
    29
  else
    30
  end
end

#last_day_of_month(month = nil) ⇒ Integer

The last day of the Gregorian month.

Parameters:

  • month (Integer) (defaults to: nil) —

    Used internally.

Returns:

  • (Integer) 


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# File 'lib/hebrew_date.rb', line 438

def last_day_of_month(month=nil)
  month ||= @month
  case month
    when 2
      if (((@year.remainder(4)) == 0) && ((@year.remainder(100)) != 0)) ||
        ((@year.remainder(400)) == 0)
        29
      else
        28
      end
    when 4, 6, 9, 11
      30
    else
      31
  end
end

#last_month_of_hebrew_year ⇒ Integer

The last month in this Hebrew year (12 or 13).

Returns:

  • (Integer) 


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# File 'lib/hebrew_date.rb', line 485

def last_month_of_hebrew_year
  self.class.last_month_of_hebrew_year(@hebrew_year)
end

#next ⇒ HebrewDate Also known as: succ

This does not modify the current date, but creates a new one.

Returns:



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# File 'lib/hebrew_date.rb', line 290

def next
  self + 1
end

#next_hebrew_month ⇒ HebrewDate

This does not modify the current date, but creates a new one.

Returns:



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# File 'lib/hebrew_date.rb', line 296

def next_hebrew_month
  current_month = self.hebrew_month
  date = self.clone
  date.forward while date.hebrew_month == current_month
  date
end

#prev_hebrew_month ⇒ HebrewDate

This does not modify the current date, but creates a new one.

Returns:



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# File 'lib/hebrew_date.rb', line 305

def prev_hebrew_month
  current_month = self.hebrew_month
  date = self.clone
  date.back while date.hebrew_month == current_month
  date
end

#set_date(year, month, date) ⇒ void

This method returns an undefined value.

Set the Gregorian date of this HebrewDate.

Parameters:

  • year (Integer) —

    the Gregorian year (e.g. 2004)

  • month (Integer) —

    the Gregorian month (1-12)

  • date (Integer) —

    the Gregorian day of month (1-31)



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# File 'lib/hebrew_date.rb', line 183

def set_date(year, month, date)
  # precond should be 1->12 anyways, but just in case...
  return "Illegal value for year: #{year}" if year < 0
  return "Illegal value for month: #{month}" if month > 12 || month < 0
  return "Illegal value for date: #{date}" if date < 0

  # make sure date is a valid date for the given month.
  # If not, set to last day of month
  last_day = last_day_of_month(month)
  date = last_day if date > last_day

  @year = year
  @month = month
  @date = date

# init the Hebrew date
  @abs_date = _date_to_abs_date(@year, @month, @date)
  _abs_date_to_hebrew_date!
end

#set_hebrew_date(year, month, date, auto_set = false) ⇒ void

This method returns an undefined value.

Set the Hebrew date.

Parameters:

  • year (Integer) —

    the Hebrew year (e.g. 2008)

  • month (Integer) —

    the Hebrew month (1-13)

  • date (Integer) —

    the Hebrew day of month (1-30)

  • auto_set (Boolean) (defaults to: false) —

    Used internally.



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# File 'lib/hebrew_date.rb', line 209

def set_hebrew_date(year, month, date, auto_set=false)
  if auto_set
    @hebrew_year = year
    @hebrew_month = month
    @hebrew_date = date
  end
  return "Illegal value for Hebrew year: #{year}" if year < 0
  if month < 0 || month > last_month_of_hebrew_year
    return "Illegal value for Hebrew month: #{month}"
  end
  return "Illegal value for Hebrew date: #{date}" if date < 0

  # make sure date is valid for this month;
  # otherwise, set to last day of month
  last_day = last_day_of_hebrew_month(month)
  date = last_day if date > last_day

  @hebrew_year = year
  @hebrew_month = month
  @hebrew_date = date

  # reset gregorian date
  @abs_date =
    _hebrew_date_to_abs_date(@hebrew_year, @hebrew_month, @hebrew_date)
  _abs_date_to_date!

end

#shabbos? ⇒ Boolean Also known as: shabbat?

Returns:

  • (Boolean) 


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# File 'lib/hebrew_date.rb', line 377

def shabbos?
  self.saturday?
end

#step(limit, step = 1, &block) ⇒ Object

Iterates evaluation of the given block, which takes a HebrewDate object. The limit should be a Date or HebrewDate object.



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# File 'lib/hebrew_date.rb', line 144

def step(limit, step=1, &block)
  return to_enum(:step, limit, step) unless block_given?
  (self..limit).step(step) { |date| yield(date) }
end

#strftime(format) ⇒ String

Extend the Date strftime method by replacing Hebrew fields. You can denote Hebrew fields by using the * flag. There is one extra flag, %.b, which adds a period after the 3-letter month name except for May. Also note that ::replace_saturday will replace the %A, %^A, %a and %^a flags with Shabbat/Shabbos. Supported flags are:

* *Y - Hebrew year
* *m - Hebrew month, zero-padded
* *_m - Hebrew month, blank-padded
* *-m - Hebrew month, no-padded
* *B - Hebrew month, full name
* *^B - Hebrew month, full name uppercase
* *b - Hebrew month, 3 letters
* *^b - Hebrew month, 3 letters uppercase
* *h - same as %*b
* *d - Hebrew day of month, zero-padded
* *-d - Hebrew day of month, no-padded
* *e - Hebrew day of month, blank-padded
* %.b - Gregorian month, 3 letter name, followed by a period, except for
   May

Parameters:

  • format (String)

Returns:

  • (String) 


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# File 'lib/hebrew_date.rb', line 405

def strftime(format)
  format = format.gsub('*Y', @hebrew_year.to_s)
    .gsub('*m', @hebrew_month.to_s.rjust(2, '0'))
    .gsub('*_m', @hebrew_month.to_s.rjust(2, ' '))
    .gsub('*-m', @hebrew_month.to_s)
    .gsub('*B', hebrew_month_to_s)
    .gsub('*^B', hebrew_month_to_s.upcase)
    .gsub('*b', hebrew_month_to_s[0, 3])
    .gsub('*^b', hebrew_month_to_s[0, 3].upcase)
    .gsub('*h', hebrew_month_to_s[0, 3])
    .gsub('*d', @hebrew_date.to_s.rjust(2, '0'))
    .gsub('*-d', @hebrew_date.to_s)
    .gsub('*e', @hebrew_date.to_s.rjust(2, ' '))
    .gsub('%.b', self.month == 5 ? '%b' : '%b.')
  if self.class.replace_saturday && self.day == 7
    shab_name = self.class.ashkenaz ? 'Shabbos' : 'Shabbat'
    format = format.gsub('%A', shab_name)
      .gsub('%^A', shab_name.upcase)
      .gsub('%a', shab_name[0..2])
      .gsub('%^a', shab_name[0..2].upcase)
  end
  super(format)
end

#to_date ⇒ Date

Return a Ruby Date corresponding to the Gregorian date.

Returns:

  • (Date) 


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# File 'lib/hebrew_date.rb', line 239

def to_date
  Date.new(@year, @month, @date)
end

#upto(max, &block) ⇒ Enumerator|self

This method is equivalent to step(max, 1){ |date| …}.

Parameters:

  • max (Integer)

Returns:

  • (Enumerator|self) 


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# File 'lib/hebrew_date.rb', line 160

def upto(max, &block)
  return to_enum(:upto, max) unless block_given?
  self.step(max, 1, &block)
end