javascript regex iso datetime

Question

does anyone have a good regex pattern for matching iso datetimes?

ie: 2010-06-15T00:00:00

Answer 1

I have made this regex and solves the validation for dates as they come out of Javascript's .toISOString() method.

^[0-9]{4}-((0[13578]|1[02])-(0[1-9]|[12][0-9]|3[01])|(0[469]|11)-(0[1-9]|[12][0-9]|30)|(02)-(0[1-9]|[12][0-9]))T(0[0-9]|1[0-9]|2[0-3]):(0[0-9]|[1-5][0-9]):(0[0-9]|[1-5][0-9])\.[0-9]{3}Z$

Contemplated:

• Proper symbols ('-', 'T', ':', '.', 'Z') in proper places.
• Consistency with months of 29, 30 or 31 days.
• Hours from 00 to 23.
• Minutes and seconds from 00 to 59.
• Milliseconds from 000 to 999.

Not contemplated:

• Leap years.

Example date: 2019-11-15T13:34:22.178Z

Example to run directly in Chrome console: /^[0-9]{4}-((0[13578]|1[02])-(0[1-9]|[12][0-9]|3[01])|(0[469]|11)-(0[1-9]|[12][0-9]|30)|(02)-(0[1-9]|[12][0-9]))T(0[0-9]|1[0-9]|2[0-3]):(0[0-9]|[1-5][0-9]):(0[0-9]|[1-5][0-9])\.[0-9]{3}Z$/.test("2019-11-15T13:34:22.178Z");

Regex flow diagram (Regexper):

Answer 2

Here is a regular expression to check ISO 8601 date format including leap years and short-long months. To run this, you'll need to "ignore white-space". A compacted version without white-space is on regexlib: http://regexlib.com/REDetails.aspx?regexp_id=3344

There's more to ISO 8601 - this regex only cares for dates, but you can easily extend it to support time validation which is not that tricky.

Update: This works now with javascript (without lookbehinds)

  ^(?:
      (?=
            [02468][048]00
            |[13579][26]00
            |[0-9][0-9]0[48]
            |[0-9][0-9][2468][048]
            |[0-9][0-9][13579][26]              
      )

      \d{4}

      (?:

        (-|)

        (?:

            (?:
                00[1-9]
                |0[1-9][0-9]
                |[1-2][0-9][0-9]
                |3[0-5][0-9]
                |36[0-6]
            )
            |
                (?:01|03|05|07|08|10|12)
                (?:
                  \1
                  (?:0[1-9]|[12][0-9]|3[01])
                )?            
            |
                (?:04|06|09|11)
                (?:
                  \1
                  (?:0[1-9]|[12][0-9]|30)
                )?            
            |
                02
                (?:
                  \1
                  (?:0[1-9]|[12][0-9])
                )?

            |
                W(?:0[1-9]|[1-4][0-9]|5[0-3])
                (?:
                  \1
                  [1-7]
                )?

        )            
      )?
  )$
  |
  ^(?:
      (?!
            [02468][048]00
            |[13579][26]00
            |[0-9][0-9]0[48]
            |[0-9][0-9][2468][048]
            |[0-9][0-9][13579][26]              
      )

      \d{4}

      (?:

        (-|)

        (?:

            (?:
                00[1-9]
                |0[1-9][0-9]
                |[1-2][0-9][0-9]
                |3[0-5][0-9]
                |36[0-5]
            )
            |
                (?:01|03|05|07|08|10|12)
                (?:
                  \2
                  (?:0[1-9]|[12][0-9]|3[01])
                )?

            |
                (?:04|06|09|11)
                (?:
                  \2
                  (?:0[1-9]|[12][0-9]|30)
                )?
            |
                (?:02)
                (?:
                  \2
                  (?:0[1-9]|1[0-9]|2[0-8])
                )?
            |
                W(?:0[1-9]|[1-4][0-9]|5[0-3])
                (?:
                  \2
                  [1-7]
                )?
       ) 
    )?
)$

To cater for time, add something like this to the mixture (from: http://underground.infovark.com/2008/07/22/iso-date-validation-regex/ ):

([T\s](([01]\d|2[0-3])((:?)[0-5]\d)?|24\:?00)?(\15([0-5]\d))?([zZ]|([\+-])([01]\d|2[0-3]):?([0-5]\d)?)?)?

Answer 3

yyyy-MM-dd

Too much explanation for most of the answers here, here's a short variation of @Sergey answer addressing some weird scenarios (like 2020-00-00), this RegExp only cares about the yyyy-MM-dd date:

// yyyy-MM-dd
^\d{4}-([0][1-9]|1[0-2])-([0-2][1-9]|[1-3]0|3[01])$

Also this one doesn't care about the number of days per month, like 2020-11-31 (because November has only 30 days).

My use-case was to convert a String into a Date (from an API param) and I needed only to know that the input string didn't contained strange stuff, I do the next validation against an actual Date object.

Answer 4

For matching just ISO date, like 2017-09-22, you can use this regexp:

^\d{4}-([0]\d|1[0-2])-([0-2]\d|3[01])$

It will match any numeric year, any month specified by two digits in range 00-12 and any date specified by two digits in range 00-31

Answer 5

with 02/29 validation from the year 1900 to 2999

 (((2000|2400|2800|((19|2[0-9])(0[48]|[2468][048]|[13579][26])))-02-29)|(((19|2[0-9])[0-9]{2})-02-(0[1-9]|1[0-9]|2[0-8]))|(((19|2[0-9])[0-9]{2})-(0[13578]|10|12)-(0[1-9]|[12][0-9]|3[01]))|(((19|2[0-9])[0-9]{2})-(0[469]|11)-(0[1-9]|[12][0-9]|30)))T([01][0-9]|[2][0-3]):[0-5][0-9]:[0-5][0-9]\.[0-9]{3}Z

Answer 6

I reworked the top answer into something a bit more concise. Instead of writing out each of the three optional patterns, the elements are nested as optional statements.

/[+-]?\d{4}(-[01]\d(-[0-3]\d(T[0-2]\d:[0-5]\d:?([0-5]\d(\.\d+)?)?[+-][0-2]\d:[0-5]\dZ?)?)?)?/

I'm curious if there are downsides to this approach?

You can find tests for my suggested answer here: http://regexr.com/3e0lh