Helper to show distance between 2 DateTime.

time_distance_helper.rb

module TimeDistanceHelper  
  def date_time_distance(start_date_time,end_date_time)
    seconds_distance = (end_date_time - start_date_time).to_i.abs
    
    days_distance = (seconds_distance / (3600 * 24)).to_i
    seconds_distance -= days_distance * 3600 * 24
    
    hours_distance = (seconds_distance / 3600).to_i
    seconds_distance -= hours_distance * 3600
    
    minutes_distance = (seconds_distance / 60).to_i
    seconds_distance -= minutes_distance * 60
  
    if days_distance >= 10
      "#{days_distance}d"
    elsif days_distance > 0
      "#{days_distance}d #{hours_distance}h"
    elsif hours_distance >= 10
      "#{hours_distance}h"
    elsif hours_distance > 0
      "#{hours_distance}h #{minutes_distance}m"
    elsif minutes_distance > 0
      "#{minutes_distance}m"
    else
      "-"
    end
  end
end