Convert 12 hr time to 24 hr format in Ruby

Question

How do I convert \"11am\" and \"10pm\" into \"11:00\" and \"22:00\"? Is there a simple way using the date and time classes?

Answer 1

I would first parse the string with Time#strptime and then output it with Time#strftime. This ensures a strict check with your original format as well.

require 'time'
Time.strptime("10pm", "%I%P").strftime("%H:%M")
=> "22:00"

Answer 2

Are you saying you want 11am and 10pm and then the ability to 11:00 and 22:00 or do you want how to show 11:00 and 22:00 instead of 11am and 10pm?

if its the second question here:

%H - Hour of the day, 24-hour clock (00 to 23).

#!/usr/bin/ruby -w
time = Time.new

puts time.to_s
puts time.ctime
puts time.localtime
puts time.strftime("%H:%M")

if its the first question tell:

%I Hour of the day, 12-hour clock (01 to 12).

#!/usr/bin/ruby -w
time = Time.new
timeSwitch = 1

if (timeSwitch == 1)
    puts time.strftime("%H:%M")
else 
    puts time.strftime("%I:%M")
end

Sorry about that had perl and ruby mixed up on syntax

Answer 3

Your question is unclear, but it sounds like you have a string "10pm", and you need to (1) capture it as a Time, and (2) represent that Time in 24-hour format. I would do it like this. First, gem install chronic, then, write a script like this:

require 'chronic'
t = Chronic.parse('10pm')
p t.strftime("%H:%M")

Returns "22:00"

Answer 4

The Time class has no parse method, but DateTime has.

require 'date'
DateTime.parse("11pm").strftime("%H:%M") #=> "23:00"