A quick script you can use to get the release dates for all the gems in your gem file

bundle-dates

#!/usr/bin/env ruby

require "open3"
require "debug"
require 'strscan'
require 'json'
require 'time'

bundle_list, _status = Open3.capture2e("bundle list")

gem_name_regex = /([\w-]+) \(([\d\.]+)\)/

scanner = StringScanner.new(bundle_list)

VersionInfo = Data.define(:name, :version, :created_at)

versions = []

while scanner.exist?(gem_name_regex)
  scanner.scan_until(gem_name_regex)
  name = scanner[1]
  version = scanner[2]
  curl_result, _status = Open3.capture2e("curl https://rubygems.org/api/v1/versions/#{name}.json -s")

  version_details = JSON.parse(curl_result).find{|detail| detail["number"] == version }
  created_at = Time.parse(version_details["created_at"])

  version_info = VersionInfo.new(name: name, version: version, created_at: created_at)
  puts version_info.to_h
  versions << version_info
end

puts versions.sort_by(&:created_at).map(&:to_h)