Time Ago Method for Ruby on Rails
Updated 2008-09-03 – This article is super old but as it comes up pretty high on in search pages for "rails time" and "rails time ago" I should probably note rails has this code in it as a helper: time_ago_in_words
I recently searched for a Ruby or Ruby on Rails method to display date and time ago ala Typo, ex: “Posted 10 minutes ago”. As it turns out Typo uses Javascript to handle this.
Typo’s js_distance_of_time_in_words_to_now
Typo uses the method js_distance_of_time_in_words_to_now which results in something like this:
<abbr class="published" title="2007-04-05T12:37:00-04:00"><span class="typo_date" title="Thu, 05 Apr 2007 16:37:00 GMT">Thu, 05 Apr 2007 16:37:00 GMT</span></abbr>
This is then parsed out to the users local time using javascript.
Rails Time Conversion API
I was surprised that Rails didn’t include something like this out of the box. The API docs refer to a number of convenience methods for handling time like since, ago, months_ago, years_ago, etc. but these don’t do what I want, instead the may it easy to use Numeric time conversions, for example: 5.month_ago returns a Time object set to 5 months ago.
Time as an adjective
What I really needed was time described in human readable terms with an adjective. Like 5 days ago, 10 minutes ago, 3 years ago, etc. So I googled around and found a reference to a timeago module written for Drupal http://zertox.com/topic/drupal/drupal_module_time_ago. I ported it to Ruby and placed it in my application helper, and it seems to work as intended.
# :start_date, sets the time to measure against, defaults to now
# :later, changes the adjective and measures time forward
# :round, sets the unit of measure 1 = seconds, 2 = minutes, 3 hours, 4 days, 5 weeks, 6 months, 7 years (yuck!)
# :max_seconds, sets the maximimum practical number of seconds before just referring to the actual time
# :date_format, used with <tt>to_formatted_s<tt>
def timeago(original, options = {})
start_date = options.delete(:start_date) || Time.now
later = options.delete(:later) || false
round = options.delete(:round) || 7
max_seconds = options.delete(:max_seconds) || 32556926
date_format = options.delete(:date_format) || :default
# array of time period chunks
chunks = [
[60 * 60 * 24 * 365 , "year"],
[60 * 60 * 24 * 30 , "month"],
[60 * 60 * 24 * 7, "week"],
[60 * 60 * 24 , "day"],
[60 * 60 , "hour"],
[60 , "minute"],
[1 , "second"]
]
if later
since = original.to_i – start_date.to_i
else
since = start_date.to_i – original.to_i
end
time = []
if since < max_seconds
# Loop trough all the chunks
totaltime = 0
for chunk in chunks[0..round]
seconds = chunk[0]
name = chunk[1]
count = ((since – totaltime) / seconds).floor
time << pluralize(count, name) unless count == 0
totaltime += count * seconds
end
if time.empty?
"less than a #{chunks[round-1][1]} ago"
else
"#{time.join(’, ‘)} #{later ? ‘later’ : ‘ago’}"
end
else
original.to_formatted_s(date_format)
end
end
This yields results like 1 week, 18 hours ago. I think it works pretty well but I wanted it a little more vague like how Typo does it, so I ported the Typo methods from Javascript to Ruby.
Ruby on Rails Time Ago
# :start_date, sets the time to measure against, defaults to now
# :date_format, used with <tt>to_formatted_s<tt>, default to :default
def timeago(time, options = {})
start_date = options.delete(:start_date) || Time.new
date_format = options.delete(:date_format) || :default
delta_minutes = (start_date.to_i – time.to_i).floor / 60
if delta_minutes.abs <= (8724*60) # eight weeks… I’m lazy to count days for longer than that
distance = distance_of_time_in_words(delta_minutes);
if delta_minutes < 0
"#{distance} from now"
else
"#{distance} ago"
end
else
return "on #{system_date.to_formatted_s(date_format)}"
end
end
def distance_of_time_in_words(minutes)
case
when minutes < 1
"less than a minute"
when minutes < 50
pluralize(minutes, "minute")
when minutes < 90
"about one hour"
when minutes < 1080
"#{(minutes / 60).round} hours"
when minutes < 1440
"one day"
when minutes < 2880
"about one day"
else
"#{(minutes / 1440).round} days"
end
end
The result is a nice vague string that rounds to the nearest unit of measure without being overly specific.
Enjoy!
