A simple ruby time ago convert

time_ago_in_words

MINUTE = 60
HOUR = MINUTE*60
DAY = HOUR*24
WEEK = DAY*7
MONTH = DAY*30
YEAR = MONTH*12

def time_ago_in_words(near_time, far_time)
  diff =  near_time.to_i - far_time.to_i

  str = ''
  case diff
  when 0..MINUTE
    str = 'now'
  when MINUTE..HOUR
    str = "#{diff / MINUTE} minutes ago"  
  when HOUR..DAY
    str = "#{diff / HOUR} hours ago"  
  when DAY..WEEK
    str = "#{diff / DAY} days ago"  
  when WEEK..MONTH
    str = "#{diff / WEEK} weeks ago"  
  when MONTH..YEAR
    str = "#{diff / MONTH} month ago"  
  when YEAR..YEAR*20
    str = "#{diff / YEAR} years ago"  
  else
    str = "long long time ago"
  end
  str
end


now = Time.now
puts time_ago_in_words(now, Time.local(2000, "jan", 1, 20, 15, 1))
puts time_ago_in_words(now, Time.local(2014, "jan", 1, 20, 15, 1))
puts time_ago_in_words(now, Time.now)
puts time_ago_in_words(now, Time.local(now.year-1, "jan", 1, 20, 15, 1))
puts time_ago_in_words(now, Time.local(now.year, now.month-1, 1, 20, 15, 1))
puts time_ago_in_words(now, Time.local(now.year, now.month, now.day-1, now.hour, now.min , 1))
puts time_ago_in_words(now, Time.local(now.year, now.month, now.day, now.hour-1, 15, 1))
puts time_ago_in_words(now, Time.local(now.year, now.month, now.day, now.hour, now.min-1, 1))
puts time_ago_in_words(now, Time.local(now.year, now.month, now.day, now.hour, now.min, now.sec-10))
puts time_ago_in_words(now, Time.local(now.year-21, "jan", 1, 20, 15, 1))