Posted on 2006-04-21
Medium Priority
Last Modified: 2013-12-26

Does anyone have an egrep regular expression (regex) for valid dates in the format YYYYMMDD?

It's fairly simple for basic checking, for example the DD bit could be:
[0-3][0-9] but that doesn't catch invalid days like 38.

if I write a full regex, starting with ^ and ending in $, I can then use the | (the OR option) along with a second full regex to capture the two cases of [0-2][0-9] and [3][0-1], however that is quite long. (ie. ^<full regex>$|^<second full regex>$)

Ideally I'd like to be able to do an embedded OR within a single regex to capture that 29 is a valid day by 39 is not.  But I can't figure out how to do that.

Of course, something that captured leap years and fancy stuff like that would be awesome, but I'm not holding my breath on it. :)

Thank You,
Question by:mj62mj62
LVL 85

Accepted Solution

ozo earned 1000 total points
ID: 16505936
egrep '^(19|20)[0-9][0-9](0[1-9]|1[0-2])(0[1-9]|[12][0-9]|3[01])$'

Author Comment

ID: 16506070
Impressive :)

Thanks a million,

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you use Adobe Reader X it is possible you can't open OLE PDF documents in the standard. The reason is the 'save box mode' in adobe reader X. Many people think the protected Mode of adobe reader x is only to stop the write access. But this fe…
Ready to get certified? Check out some courses that help you prepare for third-party exams.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
Whether it be Exchange Server Crash Issues, Dirty Shutdown Errors or Failed to mount error, Stellar Phoenix Mailbox Exchange Recovery has always got your back. With the help of its easy to understand user interface and 3 simple steps recovery proced…
Suggested Courses

850 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question