zabbix api history value get before 5m

zabb_history_val.rb

#! /usr/bin/env ruby

require "zabbixapi"
require "yaml"
require "time"

config = YAML.load(File.read(".zabbix/config.yml"))
zabbix_url = config['URL']
zabbix_user = config['USER']
zabbix_passwd = config['PASSWORD']
now = Time.now.strftime("%Y/%m/%d %H:%M:%S")
before = (Time.now - 300).strftime("%Y/%m/%d %H:%M:%S")
time_till = Time.parse(now)
time_from = Time.parse(before)

zbx = ZabbixApi.connect(
  :url => zabbix_url ,
  :user => zabbix_user ,
  :password => zabbix_passwd
)

history =  zbx.query(
  :method => "history.get",
  :params => {
#    :history => 0,
    :itemids => ["12345"],
    :time_from => time_from.to_i,
    :time_till => time_till.to_i,
    :output => "extend"
  }
)

val = history[0]['value']
puts val