Class: Hebruby::HebrewDate

Inherits:
Object
  • Object
show all
Defined in:
lib/hebruby.rb

Constant Summary collapse

HEBREW_EPOCH = 
347995.5
MONTH_NAMES = 
%w{none Nissan Iyar Sivan Tamuz Av Elul Tishrei Chesvan Kislev Tevet Shvat Adar Veadar}
HEB_MONTH_NAMES = 
[ nil, 'ניסן', 'אייר', 'סיון', 'תמוז', 'אב', 'אלול', 'תשרי', 
'חשון', 'כסלו', 'טבת', 'שבט', 'אדר', 'אדר א\'', 'אדר ב\'']
HEB_DAYS = 
[ nil, 'א\'', 'ב\'', 'ג\'', 'ד\'', 'ה\'', 'ו\'', 'ז\'', 'ח\'', 'ט\'', 
'י\'', 'י"א', 'י"ב', 'י"ג', 'י"ד', 'ט"ו', 'ט"ז', 'י"ז', 'י"ח', 'י"ח', 
'י"ט', 'כ\'' , 'כ"א', 'כ"ב', 'כ"ג', 'כ"ד', 'כ"ה', 'כ"ו', 'כ"ז', 'כ"ט', 'ל\'' ]
ONES = 
[ '', 'א', 'ב', 'ג', 'ד', 'ה', 'ו', 'ז', 'ח', 'ט' ]
TENS = 
[ '', 'י', 'כ', 'ל', 'מ', 'נ', 'ס', 'ע', 'פ', 'צ' ]

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(jd = nil) ⇒ HebrewDate

standard constructor from julian to hebrew date



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

def initialize(jd=nil)
  if jd
    @jd = jd
    convert_from_julian
  end
end

Instance Attribute Details

#hd ⇒ Object

Accessors for base Hebrew day, month, and year



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# File 'lib/hebruby.rb', line 36

def hd
  @hd
end

#hm ⇒ Object

Accessors for base Hebrew day, month, and year



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# File 'lib/hebruby.rb', line 36

def hm
  @hm
end

#hy ⇒ Object

Accessors for base Hebrew day, month, and year



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# File 'lib/hebruby.rb', line 36

def hy
  @hy
end

Class Method Details

.new1(hd, hm, hy) ⇒ Object

additional constructor from hebrew date to julian



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

def self.new1(hd, hm, hy)
  me = new
  me.hd = hd
  me.hm = hm
  me.hy = hy
  me.convert_from_hebrew
  return me
end

Instance Method Details

#convert_from_hebrew ⇒ Object 



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# File 'lib/hebruby.rb', line 134

def convert_from_hebrew
  @jd = to_jd(@hy, @hm, @hd).jd
end

#convert_from_julian ⇒ Object 



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

def convert_from_julian
  dateArray = jd_to_hebrew(@jd)
  @hy = dateArray[0]		
  @hm = dateArray[1]		
  @hd = dateArray[2]		
end

#day ⇒ Object 



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

def day
  return @hd
end

#heb_date ⇒ Object

Provide correct complete Hebrew display date



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# File 'lib/hebruby.rb', line 100

def heb_date
  return heb_day_name + " ב" + heb_month_name + " " + heb_year_name
end

#heb_day_name ⇒ Object

Provide correct Hebrew day display name



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# File 'lib/hebruby.rb', line 86

def heb_day_name
  return HEB_DAYS[@hd]
end

#heb_month_display_name(month) ⇒ Object

Provide correct Hebrew month display name



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# File 'lib/hebruby.rb', line 123

def heb_month_display_name(month)
  return HEB_MONTH_NAMES[month]  
end

#heb_month_name ⇒ Object

Provide correct Hebrew month display name



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# File 'lib/hebruby.rb', line 81

def heb_month_name
  return heb_month_display_name(@hm)
end

#heb_number(num) ⇒ Object

Provide correct Hebrew number display



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# File 'lib/hebruby.rb', line 105

def heb_number(num)
  return 'ט"ו' if num == 15
  return 'ט"ז' if num == 16
  if num < 10
    return '"' + ONES[ num % 10 ] 
  elsif num % 10 == 0
    return '"' + TENS[ num / 10 ]
  else
    return TENS[ num / 10 ] + '"' + ONES[ num % 10 ]
  end
end

#heb_year_name ⇒ Object

Provide correct Hebrew year display name

Raises:

  • (RangeError) 


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# File 'lib/hebruby.rb', line 91

def heb_year_name
  year = @hy
  raise RangeError, "only 5700 - 5899 supported" if year < 5700 || year >= 5900
  prefix = year / 100 == 57 ? "התש" : "התת"
  suffix = heb_number(year % 100)
  full = prefix + suffix
end

#jd ⇒ Object

return julian date converted from hebrew date



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# File 'lib/hebruby.rb', line 71

def jd
  return @jd + 1
end

#leap?(year) ⇒ Boolean

Is a given Hebrew year a leap year ?

Returns:

  • (Boolean) 


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# File 'lib/hebruby.rb', line 139

def leap?(year)
  return ((year * 7) + 1).modulo(19) < 7
end

#month ⇒ Object

Provide correct Hebrew transliterated month display name



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# File 'lib/hebruby.rb', line 61

def month
  return @hm
end

#month_days(year, month) ⇒ Object

How many days are in a given month of a given year



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# File 'lib/hebruby.rb', line 154

def month_days(year, month)
  # First of all, dispose of fixed-length 29 day months
  case
    when (month == 2 || month == 4 || month == 6 || month == 10 || month == 13)
      return 29

    # If it's not a leap year, Adar has 29 days
    when (month == 12 && !leap?(year)) then
      return 29

    # If it's Cheshvan, days depend on length of year
    when month == 8 && year_days(year).modulo(10) != 5 then
      return 29

    # Similarly, Kislev varies with the length of year
    when (month == 9 && (year_days(year).modulo(10) == 3)) then
      return 29
    
    # Nope, it's a 30 day month
    else
      return 30
  end
end

#month_display_name(month) ⇒ Object

Provide correct Hebrew transliterated month display name



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# File 'lib/hebruby.rb', line 118

def month_display_name(month)
  return MONTH_NAMES[month]  
end

#month_name ⇒ Object

Provide correct Hebrew transliterated month display name



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# File 'lib/hebruby.rb', line 76

def month_name
  return month_display_name(@hm)
end

#year ⇒ Object

return Hebrew year converted from julian date



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# File 'lib/hebruby.rb', line 66

def year
  return @hy
end

#year_days(year) ⇒ Object

How many days are in a Hebrew year ?



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# File 'lib/hebruby.rb', line 149

def year_days(year)
  return to_jd(year + 1, 7, 1) - to_jd(year, 7, 1)
end

#year_months(year) ⇒ Object

How many months are there in a Hebrew year (12 = normal, 13 = leap)



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

def year_months(year)
  return leap?(year) ? 13 : 12
end