Regex to match month name followed by year

Question

Is it possible to use a regex to match "February 2009", for example?

The restrictions are January - December, followed by 1990 - 2010. Fortunately, non-english isn't a concern. — Jeremy, Apr 16 '10 at 19:08
*followed by 1990 - 2010* — Is it intentional to have this tight upper limit? There's only 8 months left to 2011. — kennytm, Apr 16 '10 at 19:16

score 54 · Accepted Answer · answered Apr 16 '10 at 19:08

Along the lines of

\b(?:Jan(?:uary)?|Feb(?:ruary)?|...|Dec(?:ember)?) (?:19[7-9]\d|2\d{3})(?=\D|$)

that's

\b                  # a word boundary
(?:                 # non-capturing group
  Jan(?:uary)?      # Jan(uary)
  |Feb(?:ruary)?    #
  |...              # and so on
  |Dec(?:ember)?    # Dec(ember)
)                   # end group
                    # a space
(?:                 # non-capturing group
  19[7-9]\d|2\d{3}  # 1970-2999
)                   # end group
(?=\D|$)            # followed by: anything but a digit or the end of string

OBTW, 1990-2010 is `(?:199\d|20[01]\d)` – Tomalak Apr 16 '10 at 19:19 — Tomalak, Apr 16 '10 at 19:19

score 30 · Answer 2 · answered Jul 11 '14 at 07:25

30

I had to work on this to match a few fringe examples, but I ended up using

(\b\d{1,2}\D{0,3})?\b(?:Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|Jun(?:e)?|Jul(?:y)?|Aug(?:ust)?|Sep(?:tember)?|Oct(?:ober)?|(Nov|Dec)(?:ember)?)\D?(\d{1,2}\D?)?\D?((19[7-9]\d|20\d{2})|\d{2})

to capture dates with word months in them

answered Jul 11 '14 at 07:25

Beerswiller

529
5
8

4

Just a minor thing, for the months instead of (Nov|Dec) it should be (?:Nov|Dec), or at least I had to change that in order for it to work with Python otherwise it was returning an empty [''] match – Walter R Aug 03 '17 at 19:04
You can add (?i)(regex_part_to_make_case_insensitive) or (?i)regex_part_to_make_case_insensitive(?-i) depending on the regex processor you are using. – Onyr Apr 22 '21 at 16:04

Pedro Machin · Answer 3 · 2018-01-31T14:01:02.507

4

Modifying Beerswiller's answer, if you want "st"/"nd"/"rd" variations:

(\b\d{1,2}\D{0,3})?\b(?:Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|Jun(?:e)?|Jul(?:y)?|Aug(?:ust)?|Sep(?:tember)?|Oct(?:ober)?|(Nov|Dec)(?:ember)?)\D?(\d{1,2}(st|nd|rd|th)?)?(([,.\-\/])\D?)?((19[7-9]\d|20\d{2})|\d{2})*

edited Jan 31 '18 at 14:01

answered Jan 31 '18 at 13:28

Pedro Machin

51
3

It also passes 34rth July 1999 as a valid date! – Zujaj Misbah Khan Oct 20 '20 at 06:24

score 3 · Answer 4 · edited Sep 06 '18 at 15:44

3

This regex accounts for some spacing around the comma.

Sometimes it's not always in the right place.

((\b\d{1,2}\D{0,3})?\b(?:Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|Jun(?:e)?|Jul(?:y)?|Aug(?:ust)?|Sep(?:tember)?|Oct(?:ober)?|(Nov|Dec)(?:ember)?)\D?)(\d{1,2}(st|nd|rd|th)?)?((\s*[,.\-\/]\s*)\D?)?\s*((19[0-9]\d|20\d{2})|\d{2})*

edited Sep 06 '18 at 15:44

Acapulco

3,195
8
37
46

answered Sep 06 '18 at 14:49

Todd

41
1

Regex to match month name followed by year

4 Answers4

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