ParseDate
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).
Installation
Add this line to your application's Gemfile:
gem 'parse_date'And then execute:
$ bundle
Or install it yourself as:
$ gem install parse_date
Usage
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
Development
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.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/ndushay/parse_date.
Copyright
Copyright (c) 2019 Stanford Libraries. See LICENSE for details.