# TzTime thread safe?

**URL:** <https://www.ruby-forum.com/t/tztime-thread-safe/125797>\
**Category:** Rails\
**Created:** [January 12, 2008, 3:44am UTC](https://www.ruby-forum.com/t/tztime-thread-safe/125797 "2008-01-12T03:44:25Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![dnstevenson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/8dc957/32.png) [@dnstevenson](https://www.ruby-forum.com/u/dnstevenson)\
**Post date:** [January 12, 2008, 3:44am UTC](https://www.ruby-forum.com/t/tztime-thread-safe/125797/1 "2008-01-12T03:44:25Z")

</div>

The implementation of TzTime uses:

class TzTime  
class \<\<self  
attr\_accessor :zone

and then recommends doing this:

class ApplicationController \< ActionController::Base  
around\_filter :set\_timezone

private  
def set\_timezone  
TzTime.zone = current\_user.time\_zone  
yield  
TzTime.reset!  
end  
end

Won’t this cause problems with concurrent requests for two users with  
different timezones?

---

<div class="post-metadata">

**Author:** ![dnstevenson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/8dc957/32.png) [@dnstevenson](https://www.ruby-forum.com/u/dnstevenson)\
**Post date:** [January 12, 2008, 4:15am UTC](https://www.ruby-forum.com/t/tztime-thread-safe/125797/2 "2008-01-12T04:15:58Z")

</div>

AFAIK Rails doesn’t do concurrent requests.

---

<div class="post-metadata">

**Author:** ![dnstevenson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/8dc957/32.png) [@dnstevenson](https://www.ruby-forum.com/u/dnstevenson)\
**Post date:** [January 12, 2008, 1:09pm UTC](https://www.ruby-forum.com/t/tztime-thread-safe/125797/3 "2008-01-12T13:09:42Z")

</div>

Rails is not thread safe. Thats why we have to use mongrel\_cluster . I  
believe Merb IS threaded if you’re worried about concurrency. It is  
also a lot faster!