# Difference between 2 dates

**URL:** <https://www.ruby-forum.com/t/difference-between-2-dates/148598>\
**Category:** Ruby\
**Created:** [September 15, 2008, 2:17pm UTC](https://www.ruby-forum.com/t/difference-between-2-dates/148598 "2008-09-15T14:17:06Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![srinu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f475e1/32.png) [@srinu](https://www.ruby-forum.com/u/srinu)\
**Post date:** [September 15, 2008, 2:17pm UTC](https://www.ruby-forum.com/t/difference-between-2-dates/148598/1 "2008-09-15T14:17:06Z")

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Hi all,

duration\_val= Time.now.strftime("%Y-%m-%d %H:%M:%S")-start\_time\_Val

Start\_time\_val formate is also same formate ("%Y-%m-%d %H:%M:%S").

I could not able to subtract 2 datetimes . Please suggest me .

I am getting error like this  
undefined method `-’ for “2008-09-15 17:46:54”:String

My mail id:  
removed\_email\_address@domain.invalid

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<div class="post-metadata">

**Author:** ![srinu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f475e1/32.png) [@srinu](https://www.ruby-forum.com/u/srinu)\
**Post date:** [September 15, 2008, 2:31pm UTC](https://www.ruby-forum.com/t/difference-between-2-dates/148598/2 "2008-09-15T14:31:36Z")

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2008/9/15 Srinivasa R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> undefined method `-’ for “2008-09-15 17:46:54”:String  
> As the error indicates: you need to subtract Time values and not String  
> values.

Cheers

robert