Simple tool to calculate distance between Debian releases (and freezes)

Debian Timescale Output

--- Debian history ---
Version 0.93R6 was released 1995-10-26
  235 days (0.64384 years) later came Version 1.1 (buzz)
  178 days (0.48767 years) later came Version 1.2 (rex)
  175 days (0.47945 years) later came Version 1.3 (bo)
  414 days (1.13425 years) later came Version 2.0 (hamm)
  228 days (0.62466 years) later came Version 2.1 (slink)
  525 days (1.43836 years) later came Version 2.2 (potato) (freeze time: 212 days)
  703 days (1.92603 years) later came Version 3.0 (woody) (freeze time: 383 days)
 1053 days (2.88493 years) later came Version 3.1 (sarge) (freeze time: 34 days)
  671 days (1.83836 years) later came Version 4.0 (etch) (freeze time: 243 days)
  679 days (1.86027 years) later came Version 5.0 (lenny) (freeze time: 203 days)
  721 days (1.97534 years) later came Version 6.0 (squeeze) (freeze time: 184 days)
  731 days (2.00274 years) later maybe comes Version 7.0 (wheezy) (freeze time: 221 days)
  730 days (2.00000 years) later maybe comes Version 8.0? (jessie)

debian-timescale.rb

#!/usr/bin/ruby

require 'date'

class DebianRelease
	def initialize(version, name, release, freeze = nil)
		@version = version
		@name = name
		@release = release
		@freeze = freeze
	end

	attr_reader :version, :name, :release, :freeze

	def to_s
		@version + ((@name)?" (%s)" % @name:"")
	end

	def -(other)
		@release - other.release
	end
end

data = [
	DebianRelease.new("0.93R6", nil,     Date::civil(1995, 10, 26)),
#	DebianRelease.new("no 1.0", nil,     Date::civil(1995, 12, 11)),
	DebianRelease.new("1.1",  "buzz",    Date::civil(1996,  6, 17)),
	DebianRelease.new("1.2",  "rex",     Date::civil(1996, 12, 12)),
	DebianRelease.new("1.3",  "bo",      Date::civil(1997,  6,  5)),
	DebianRelease.new("2.0",  "hamm",    Date::civil(1998,  7, 24)),
	DebianRelease.new("2.1",  "slink",   Date::civil(1999,  3,  9), Date::civil(1998, 11,  4)),
	DebianRelease.new("2.2",  "potato",  Date::civil(2000,  8, 15), Date::civil(2000,  1, 16)),
	DebianRelease.new("3.0",  "woody",   Date::civil(2002,  7, 19), Date::civil(2001,  7,  1)),
	DebianRelease.new("3.1",  "sarge",   Date::civil(2005,  6,  6), Date::civil(2005,  5,  3)),
	DebianRelease.new("4.0",  "etch",    Date::civil(2007,  4,  8), Date::civil(2006,  8,  8)),
	DebianRelease.new("5.0",  "lenny",   Date::civil(2009,  2, 15), Date::civil(2008,  7, 27)),
	DebianRelease.new("6.0",  "squeeze", Date::civil(2011,  2,  6), Date::civil(2010,  8,  6)),
	DebianRelease.new("7.0",  "wheezy",  Date::civil(2013,  2,  6), Date::civil(2012,  6, 30)),
	DebianRelease.new("8.0?", "jessie",  Date::civil(2015,  2,  6)),
]

puts "--- Debian history ---"
last = nil
data.sort_by {|e| e.release }.each { |ver|
	if (last)
		printf "%5i days (%1.5f years) later %s Version %s", ver - last, (ver - last) / 365,
			((ver.release > Date.today)? "maybe comes" : "came"), ver
	else
		printf "Version %s was released %s", ver, ver.release
	end
	printf " (freeze time: %i days)", ver.release - ver.freeze if ver.freeze
	puts
	last = ver
}