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In Rails 3, is there a way to use datetime_select and display hours showing 12 hour am/pm options rather than 24-hour options?

Drew Johnson
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3 Answers3

8

In case anyone stumbles upon this question, the answer for rails 3.2 is: 

<%= f.datetime_select :attribute_name,  
                       ampm: true %>
Tass
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    This is the correct, Rails-supported way, but the output is an hour select with options labeled 01 AM, 02 AM, etc. which makes the set time read like "01 AM:30" which is really wonky from a user POV - almost as bad as 24-hour time. – pjmorse Apr 06 '15 at 15:01
  • I am bewildered as to why someone would program it that way. Makes no sense. The norm is 3 boxes "9 : 15 : PM" – Greg Blass Dec 03 '15 at 15:49
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    @GregBlass, we should instead switch to a 24-hour clock. ;-) – Tass Dec 03 '15 at 17:06
2

Here's the method I added to my helper class:

def am_pm_hour_select(field_name)
select_tag(field_name,options_for_select([
  ["1 AM", "01"],["2 AM", "02"],["3 AM", "03"],["4 AM", "04"],["5 AM", "05"],["6 AM", "06"],
  ["7 AM", "07"],["8 AM", "08"],["9 AM", "09"],["10 AM", "10"],["11 AM", "11"],["12 PM", "12"],
  ["1 PM", "13"],["2 PM", "14"],["3 PM", "15"],["4 PM", "16"],["5 PM", "17"],["6 PM", "18"],
  ["7 PM", "19"],["8 PM", "20"],["9 PM", "21"],["10 PM", "22"],["11 PM", "23"],["12 AM", "0"]]))
end

Then I plugged that method into my view:

<%= am_pm_hour_select "eventtime[start(4i)]" %>

It seemed to do the trick, but if there's a more idiomatic way of doing this, I'd be interested to hear.

(update: fixed bugs found by thucydides)

Drew Johnson
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2

The code below treats midnight and noon incorrectly: it calls noon '12 AM,' which is midnight; it calls midnight '12 PM,' which is noon.

Also, the code should use 0:00 as midnight, which is the international standard.

Fixed:

def am_pm_hour_select(field_name)
select_tag(field_name,options_for_select([
    ["1 AM", "01"],["2 AM", "02"],["3 AM", "03"],["4 AM", "04"],["5 AM", "05"],["6 AM", "06"],
    ["7 AM", "07"],["8 AM", "08"],["9 AM", "09"],["10 AM", "10"],["11 AM", "11"],["Noon", "12"],
    ["1 PM", "13"],["2 PM", "14"],["3 PM", "15"],["4 PM", "16"],["5 PM", "17"],["6 PM", "18"],
    ["7 PM", "19"],["8 PM", "20"],["9 PM", "21"],["10 PM", "22"],["11 PM", "23"],["Midnight", "0"]]))
end
thucydides
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