example_handler.json

{
  "handlers": {
    "example_handler": {
      "type": "pipe",
      "command": "notify_somebody.rb",
      "timeout": 30,
      "filter": "filter_weekly_maintenance"
    }
  }
}

filter_july_29_maintenance.json

{
  "filters": {
    "filter_july_29_maintenance": {
      "negate": true,
      "attributes": {
        "timestamp": "eval: Time.new(2016,7,29,18,0,0,'-06:00') < value && value < Time.new(2016,7,30,6,0,0,'-06:00')",
        "check": {
          "name": "eval: ['check_foo','check_bar','check_baz'].include?(value)"
        }
      }
    }
  }
}

filter_weekly_maintenance.json

{
  "filters": {
    "filter_weekly_maintenance": {
      "negate": true,
      "attributes": {
        "timestamp": "eval: (Time.at(value).wday == 5 && Time.at(value).hour > 18) || (Time.at(value).wday == 6 && Time.at(value).hour < 6)",
        "check": {
          "name": "eval: ['check_foo','check_bar','check_baz'].include?(value)"
        }
      }
    }
  }
}

Thank you guys so much! This is exactly what I need until scheduled maintenance is available. 😄