# Reg :regular expression

**URL:** <https://www.ruby-forum.com/t/reg-regular-expression/113938>\
**Category:** Rails\
**Created:** [September 6, 2007, 12:44pm UTC](https://www.ruby-forum.com/t/reg-regular-expression/113938 "2007-09-06T12:44:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![shiva](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/85e7bf/32.png) [@shiva](https://www.ruby-forum.com/u/shiva)\
**Post date:** [September 6, 2007, 12:44pm UTC](https://www.ruby-forum.com/t/reg-regular-expression/113938/1 "2007-09-06T12:44:12Z")

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HI,

```
how to validate a time in regular expression

```

eg: alert 9916789067 05:16 wake up

so i should validate time time can be

05:16  
0516  
05.16p  
05.16p.m or pm  
05.16a  
05.16a.m or am  
05:16a

if any one knows help me

---

<div class="post-metadata">

**Author:** ![shiva](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/85e7bf/32.png) [@shiva](https://www.ruby-forum.com/u/shiva)\
**Post date:** [September 6, 2007, 2:02pm UTC](https://www.ruby-forum.com/t/reg-regular-expression/113938/2 "2007-09-06T14:02:45Z")

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2007/9/6, Shiva K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> HI,
> 
> ```
> how to validate a time in regular expression
> 
> ```
> 
> eg: alert 9916789067 05:16 wake up
> 
> so i should validate time time can be

I didnt try it, you could try to use the validates\_format\_of  
([ActiveRecord::Validations::ClassMethods](http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html#M000945))  
method.