ParseDate is a Ruby gem that parses date values out of strings and normalizes the values for searching, faceting, display, etc. (e.g. in Solr search engine).
Add this line to your application's Gemfile:
gem 'parse_date'And then execute:
$ bundle
Or install it yourself as:
$ gem install parse_date
ParseDate has class methods for date string parsing.
require 'parse_date'
ParseDate.parse_range('12/25/00') # [2000]
ParseDate.parse_range('5-1-25') # [1925]
ParseDate.parse_range('1666 B.C.') # [-1666]
ParseDate.parse_range('-914') # [-914]
ParseDate.parse_range('[c1926]') # [1926]
ParseDate.parse_range('ca. 1558') # [1558]
ParseDate.parse_range('195-') # (1950..1959).to_a
ParseDate.parse_range('199u') # (1990..1999).to_a
ParseDate.parse_range('197?') # (1970..1979).to_a
ParseDate.parse_range('196x') # (1960..1969).to_a
ParseDate.parse_range('1990s') # (1990..1999).to_a
ParseDate.parse_range('1990s?') # (1990..1999).to_a
ParseDate.parse_range('ca. 1930s') # (1930..1939).to_a
ParseDate.parse_range('1928-1980s') # (1928..1989).to_a
ParseDate.parse_range('1940s-1990') # (1940..1990).to_a
ParseDate.parse_range('1980s-1990s') # (1980..1999).to_a
ParseDate.parse_range('1675-7') # [1675, 1676, 1677]
ParseDate.parse_range('1040–1 CE') # [1040, 1041]
ParseDate.parse_range('18th century CE') # (1700..1799).to_a
ParseDate.parse_range('17uu') # (1700..1799).to_a
ParseDate.parse_range('between 1694 and 1799') # (1694..1799).to_a
ParseDate.parse_range('between 1 and 5') # (1..5).to_a
ParseDate.parse_range('between 300 and 150 B.C.') # (-300..-150).to_a
ParseDate.parse_range('-5 - 3') # (-5..3).to_a
ParseDate.parse_range('1496-1499') # (1496..1499).to_a
ParseDate.parse_range('1750?-1867') # (1750..1867).to_a
ParseDate.parse_range('17--?-18--?') # (1700..1899).to_a
ParseDate.parse_range('1835 or 1836') # [1835, 1836]
ParseDate.parse_range('17-- or 18--?') # (1700..1899).to_a
ParseDate.parse_range('-2 or 1?') # (-2..1).to_a
ParseDate.parse_range('1500? to 1582') # (1500..1582).to_a
ParseDate.parse_range('17th or 18th century?') # (1600..1799).to_a
ParseDate.parse_range('ca. 5th–6th century A.D.') # (400..599).to_a
ParseDate.parse_range('ca. 9th–8th century B.C.') # (-999..-800).to_a
ParseDate.parse_range('ca. 13th–12th century B.C.') # (-1399..-1200).to_a
ParseDate.parse_range('5th century B.C.') # (-599..-500).to_a
ParseDate.parse_range('502-504') # [502, 503, 504]
ParseDate.parse_range('950-60') # (950..960).to_a
ParseDate.parse_range('-0150 - -0100') # (-150..-100).to_a
ParseDate.parse_range('-2100 - -2000') # (-2100..-2000).to_a
ParseDate.parse_range('1230—1239 CE') # (1230..1239).to_a (alternate hyphen char)
ParseDate.parse_range('996–1021 CE') # (996..1021).to_a (diff alternate hyphen char)
ParseDate.parse_range('1975 - 1905') # last year > first year, raises error
ParseDate.parse_range('-100 - -150') # last year > first year, raises error
ParseDate.parse_range('1975 or 1905') # last year > first year, raises error
ParseDate.parse_range('1975 - 2050') # single invalid year endpoint, raises error
ParseDate.parse_range('2050') # nil - only invalid year endpoints present
ParseDate.parse_range('2045 - 2050') # nil - only invalid year endpoints present
ParseDate.parse_range('random text') # nil - can't parse years
ParseDate.parse_range(nil) # nil - can't parse years
ParseDate.earliest_year('12/25/00') # 2000
ParseDate.earliest_year('5-1-21') # 1921
ParseDate.earliest_year('19990211') # 1999
ParseDate.earliest_year('1666 B.C.') # -1666
ParseDate.earliest_year('-914') # -914
ParseDate.earliest_year('[c1926]') # 1926
ParseDate.earliest_year('ca. 1558') # 1558
ParseDate.earliest_year('195-') # 1950
ParseDate.earliest_year('199u') # 1990
ParseDate.earliest_year('197?') # 1970
ParseDate.earliest_year('196x') # 1960
ParseDate.earliest_year('18th century CE') # 1700
ParseDate.earliest_year('17uu') # 1700
ParseDate.earliest_year('between 1694 and 1799') # 1694
ParseDate.earliest_year('between 1 and 5') # 1
ParseDate.earliest_year('between 300 and 150 B.C.') # -300
ParseDate.earliest_year('1500? to 1582') # 1500
ParseDate.earliest_year('1496-1499') # 1496
ParseDate.earliest_year('1230—1239 CE') # 1230 (alternate hyphen char)
ParseDate.earliest_year('996–1021 CE') # 996 (diff alternate hyphen char)
ParseDate.earliest_year('1750?-1867') # 1750
ParseDate.earliest_year('17--?-18--?') # 1700
ParseDate.earliest_year('1835 or 1836') # 1835
ParseDate.earliest_year('17-- or 18--?') # 1700
ParseDate.earliest_year('17th or 18th century?') # 1600
ParseDate.earliest_year('ca. 5th–6th century A.D.') # 400
ParseDate.earliest_year('ca. 9th–8th century B.C.') # -999
ParseDate.earliest_year('ca. 13th–12th century B.C.') # -1399
ParseDate.earliest_year('5th century B.C.') # -599
ParseDate.earliest_year('502-504') # 502
ParseDate.earliest_year('950-60') # 950
ParseDate.earliest_year('-0150 - -0100') # -150
ParseDate.earliest_year('-2100 - -2000') # -2100
ParseDate.latest_year('20000222') # 2000
ParseDate.latest_year('195-') # 1959
ParseDate.latest_year('199u') # 1999
ParseDate.latest_year('197?') # 1979
ParseDate.latest_year('196x') # 1969
ParseDate.latest_year('1990s') # 1999
ParseDate.latest_year('1990s?') # 1999
ParseDate.latest_year('ca. 1930s') # 1939
ParseDate.latest_year('1928-1980s') # 1989
ParseDate.latest_year('1940s-1990') # 1990
ParseDate.latest_year('1980s-1990s') # 1999
ParseDate.latest_year('1675-7') # 1677
ParseDate.latest_year('1040–1 CE') # 1041
ParseDate.latest_year('18th century CE') # 1799
ParseDate.latest_year('17uu') # 1799
ParseDate.latest_year('between 1694 and 1799') # 1799
ParseDate.latest_year('between 1 and 5') # 5
ParseDate.latest_year('between 300 and 150 B.C.') # -150
ParseDate.latest_year('1500? to 1582') # 1582
ParseDate.latest_year('1496-1499') # 1499
ParseDate.latest_year('1230—1239 CE') # 1239 (alternate hyphen char)
ParseDate.latest_year('996–1021 CE') # 1021 (diff alternate hyphen char)
ParseDate.latest_year('1750?-1867') # 1867
ParseDate.latest_year('17--?-18--?') # 1899
ParseDate.latest_year('1757-58') # 1758
ParseDate.latest_year('1975-05') # 1975 (range invalid)
ParseDate.latest_year('1835 or 1836') # 1836
ParseDate.latest_year('17-- or 18--?') # 1899
ParseDate.latest_year('17th or 18th century?') # 1799
ParseDate.latest_year('ca. 5th–6th century A.D.') # 599
ParseDate.latest_year('ca. 9th–8th century B.C.') # -800
ParseDate.latest_year('ca. 13th–12th century B.C.') # -1200
ParseDate.latest_year('5th century B.C.') # -500
ParseDate.latest_year('-5 - 3') # 3
ParseDate.latest_year('502-504') # 504
ParseDate.latest_year('950-60') # 960
ParseDate.latest_year('-0150 - -0100') # -100
ParseDate.latest_year('-2100 - -2000') # -2000
ParseDate.range_array('1993', '1995') # [1993, 1994, 1995]
ParseDate.range_array(1993, 1995) # [1993, 1994, 1995]
ParseDate.range_array(0, '0001') # [0, 1]
ParseDate.range_array('-0003', '0000') # [-3, -2, -1, 0]
ParseDate.range_array(-1, 1) # [-1, 0, 1]
ParseDate.range_array(15, 15) # [15]
ParseDate.range_array(-100, '-99') # [-100, -99]
ParseDate.range_array('98', 101) # [98, 99, 100, 101]
ParseDate.range_array('word1', 'word2') # throws ArgumentError
ParseDate.range_array('1993', 1990) # throws StandardError - bad range
ParseDate.year_range_valid?(1975, 1905) # false, first year > last year
ParseDate.year_range_valid?(-100, -150) # false, first year > last year
ParseDate.year_range_valid?(2050, 2070) # false, year later than current year + 1
ParseDate.year_range_valid?(2007, 2050) # false, year later than current year + 1
ParseDate.year_range_valid?(2007, 2009) # true
ParseDate.year_range_valid?(75, 150) # true
ParseDate.year_range_valid?(-3, 2) # true
ParseDate.year_range_valid?(-100, -50) # true
ParseDate.year_range_valid?(-1500, -1499) # true
ParseDate.year_range_valid?(-15000, -14999) # true
ParseDate.year_int_valid?(0) # true
ParseDate.year_int_valid?(5) # true
ParseDate.year_int_valid?(33) # true
ParseDate.year_int_valid?(150) # true
ParseDate.year_int_valid?(2019) # true
ParseDate.year_int_valid?(Date.today.year + 1) # true
ParseDate.year_int_valid?(-3) # true
ParseDate.year_int_valid?(-35) # true
ParseDate.year_int_valid?(-999) # true
ParseDate.year_int_valid?(-1666) # false - four digit negative years not considered valid here
ParseDate.year_int_valid?(165x) # false
ParseDate.year_int_valid?(198-) # false
ParseDate.year_int_valid?('random text') # false
ParseDate.year_int_valid?(nil) # false
After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/ndushay/parse_date.
Copyright (c) 2019 Stanford Libraries. See LICENSE for details.