Calculate Difference in time in Days, Hours, Minutes, Seconds

display_time.rb

 def display_time(total_seconds)
    total_seconds = total_seconds.to_i
    
    days = total_seconds / 86400
    hours = (total_seconds / 3600) - (days * 24)
    minutes = (total_seconds / 60) - (hours * 60) - (days * 1440)
    seconds = total_seconds % 60
    
    display = ''
    display_concat = ''
    if days > 0
      display = display + display_concat + "#{days}d"
      display_concat = ' '
    end
    if hours > 0 || display.length > 0
      display = display + display_concat + "#{hours}h"
      display_concat = ' '
    end
    if minutes > 0 || display.length > 0
      display = display + display_concat + "#{minutes}m"
      display_concat = ' '
    end
    display = display + display_concat + "#{seconds}s"
    display
  end

Nice! This problem comes up often. I solved it in SQL awhile back.