proc creating and order of defination of local variable

foo.rb

default = Proc.new { { :foo => 12, :bar => "0.0.0.0/thank-you/#{encoded_time}" } }
encoded_time = "15_32"

begin
  puts default.call
rescue
  puts "#~ undefined local variable or method `encoded_time'"
  puts "proc does not pick up the local variable defined after proc creation"
end

puts ""
puts "--------"
puts ""

default = Proc.new { { :foo => 12, :bar => "0.0.0.0/thank-you/#{encoded_time}" } }
puts default.call #{:foo=>12, :bar=>"0.0.0.0/thank-you/15_32"}
puts "but works now that the local variable is defined before creating the proc"

puts ""
puts "--------"
puts ""

puts "reassigning the lvar"
encoded_time = "16_32"
# proc enclosed over the variable but it takes up the changed value
puts default.call #{:foo=>12, :bar=>"0.0.0.0/thank-you/16_32"}

puts ""
puts "--------"
puts ""

default = Proc.new { { :foo => 12, :bar => "0.0.0.0/thank-you/#{@request_time}" } }
puts default.call #{:foo=>12, :bar=>"0.0.0.0/thank-you/"}

@request_time = "17_32"
puts default.call #{:foo=>12, :bar=>"0.0.0.0/thank-you/16_32"}

puts "but there is no such restriction on using ivars because undefined ivars show as nil not a undefined error"

puts ""
puts "--------"
puts ""

puts "reassigning the ivar"
@request_time = "18_32"
puts default.call #{:foo=>12, :bar=>"0.0.0.0/thank-you/18_32"}