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I am running into what to me seems like a simple issue, but I can't figure out what I am doing wrong. In my app users can add their course through a simple form_for. They can enter a start_time and end_time for the course's lectures, like so:

<div class="field">
  Start Time<br />
  <%= time_select :course, :start_time, { :minute_step => 5, :ampm => true } %>
</div>

<div class="field">
  End Time<br />
  <%= time_select :course, :end_time, { :minute_step => 5, :ampm => true } %>
</div>

I configured my time zone in application.rb to be set to Eastern Time and this seems to work correctly as created_at is returned in the right time zone.

However, the problem I am encountering is that start_time and end_time are entered as UTC into the database. So when a user selects a class to start at 10 AM it is entered as 10 UTC not 10 AM EST / 15:00 UTC. What am I missing here? It seems like what I want to happen should be possible.

Philip V
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  • Maybe this helps you: http://stackoverflow.com/questions/4362663/timezone-with-rails-3 – Tim Brandes Jan 05 '12 at 16:59
  • I actually think I have the opposite problem. My start_time and end_time are not being saved within the time zone but saved as a UTC time. – Philip V Jan 05 '12 at 17:10
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    I have never used a time_select but always a datetime_select when dealing with timezones, maybe this could be an issue, but it seems rather unlikely. – Tim Brandes Jan 05 '12 at 17:23
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    Your idea actually set me on the right track. I changed the column type for start_time and end_time to datetime and this fixed the issues I had. I guess time columns only allow UTC. – Philip V Jan 05 '12 at 17:56
  • @TimBrandes or PhilipV - If you're game to recap the solution as your own answer, I'll delete my answer. (See http://meta.stackexchange.com/questions/90263/unanswered-question-answered-in-comments for elaboration of why this is helpful.) Thanks! – DreadPirateShawn Oct 09 '13 at 16:19

2 Answers2

2

Summarizing the answer from the comments in order to remove this question from the "Unanswered" filter:

Suggested by Tim Brandes:

Maybe this helps you: Timezone with rails 3 ... I have never used a time_select but always a datetime_select when dealing with timezones, maybe this could be an issue, but it seems rather unlikely.

Solution that worked for Philip V:

My start_time and end_time are not being saved within the time zone but saved as a UTC time. ... I changed the column type for start_time and end_time to datetime and this fixed the issues I had. I guess time columns only allow UTC.

Community
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DreadPirateShawn
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0

I was struggling with the same problem. But then I realized I didn't need the timezone information of the Time object.

As you said, the database stores it as UTC, but the really important thing we need to do with this data is:

course.start_time.hour
course.start_time.min

This is timezone independent. (8 hours is 8 hours from midnight, no matter what midnight you're comparing. 30 minutes is 30 minutes from the minute 0 of the hour. No matter in what timezone is that hour you're using).

So in most applications where the need of a Time storage structure is required, like to know when a recurrent event starts or finish, to store the value of a timer, or a the time of a lap in a race, you can use the UTC Time the database returns with no problem.

João Paulo Motta
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  • Agreed, in general. In the case of running a scheduled job at a certain time of the day, where the system time and recurring event are compared, it's an issue. In that case, storing the recurring event in UTC will yield an inaccurate comparison between the system time and recurring event time. – Tim K. Mar 11 '22 at 12:46