---
layout: page
title: "History Statistics Sensor"
description: "Instructions about how to integrate historical statistics into Home Assistant."
date: 2017-02-10 12:00
sidebar: true
comments: false
sharing: true
footer: true
logo: home-assistant.png
ha_category: Utility
ha_iot_class: "Local Polling"
ha_release: 0.39
ha_qa_scale: internal
---

The `history_stats` sensor platform provides quick statistics about another component or platforms, using data from the [history](/components/history/).

It can track how long the component has been in a specific state, in a custom time period.

Examples of what you can track:

- How long you were at home this week
- How long the lights were ON yesterday
- How long you watched TV today

## {% linkable_title Configuration %}

To enable the history statistics sensor, add the following lines to your `configuration.yaml`:

{% raw %}
```yaml
# Example configuration.yaml entry
sensor:
  - platform: history_stats
    name: Lamp ON today
    entity_id: light.my_lamp
    state: 'on'
    type: time
    start: '{{ now().replace(hour=0).replace(minute=0).replace(second=0) }}'
    end: '{{ now() }}'
```
{% endraw %}

{% configuration %}
entity_id:
  description: The entity you want to track.
  required: true
  type: string
state:
  description: The state you want to track.
  required: true
  type: string
name:
  description: Name displayed on the frontend.
  required: false
  default: unnamed statistics
  type: string
type:
  description: "The type of sensor: `time`, `ratio`, or `count`."
  required: false
  default: time
  type: string
start:
  description: When to start the measure (timestamp or datetime).
  required: false
  type: template
end:
  description: When to stop the measure (timestamp or datetime).
  required: false
  type: template
duration:
  description: Duration of the measure.
  required: false
  type: time
{% endconfiguration %}

<p class='note'>
  You have to provide **exactly 2** of `start`, `end` and `duration`.
<br/>
  You can use [template extensions](/topics/templating/#home-assistant-template-extensions) such as `now()` or `as_timestamp()` to handle dynamic dates, as shown in the examples below.
</p>

## {% linkable_title Sensor type %}

Depending on the sensor type you choose, the `history_stats` component can show different values:

- **time**: The default value, which is the tracked time, in hours
- **ratio**: The tracked time divided by the length of your period, as a percentage
- **count**: How many times the component you track was changed to the state you track

## {% linkable_title Time periods %}

The `history_stats` component will execute a measure within a precise time period. You should always provide 2 of the following :
- When the period starts (`start` variable)
- When the period ends (`end` variable)
- How long is the period (`duration` variable)

As `start` and `end` variables can be either datetimes or timestamps, you can configure almost any period you want.

### {% linkable_title Duration %}

The duration variable is used when the time period is fixed. Different syntaxes for the duration are supported, as shown below.

```yaml
# 6 hours
duration: 06:00
```

```yaml
# 1 minute, 30 seconds
duration: 00:01:30
```

```yaml
# 2 hours and 30 minutes
duration:
  # supports seconds, minutes, hours, days
  hours: 2
  minutes: 30
```

### {% linkable_title Examples %}

Here are some examples of periods you could work with, and what to write in your `configuration.yaml`:

**Today**: starts at 00:00 of the current day and ends right now.

{% raw %}
```yaml
    start: '{{ now().replace(hour=0).replace(minute=0).replace(second=0) }}'
    end: '{{ now() }}'
```
{% endraw %}

**Yesterday**: ends today at 00:00, lasts 24 hours.

{% raw %}
```yaml
    end: '{{ now().replace(hour=0).replace(minute=0).replace(second=0) }}'
    duration:
      hours: 24
```
{% endraw %}

**This morning (6AM - 11AM)**: starts today at 6, lasts 5 hours.

{% raw %}
```yaml
    start: '{{ now().replace(hour=6).replace(minute=0).replace(second=0) }}'
    duration:
      hours: 5
```
{% endraw %}

**Current week**: starts last Monday at 00:00, ends right now.

Here, last Monday is _today_ as a timestamp, minus 86400 times the current weekday (86400 is the number of seconds in one day, the weekday is 0 on Monday, 6 on Sunday).

{% raw %}
```yaml
    start: '{{ as_timestamp( now().replace(hour=0).replace(minute=0).replace(second=0) ) - now().weekday() * 86400 }}'
    end: '{{ now() }}'
```
{% endraw %}

**Last 30 days**: ends today at 00:00, lasts 30 days. Easy one.

{% raw %}
```yaml
    end: '{{ now().replace(hour=0).replace(minute=0).replace(second=0) }}'
    duration:
      days: 30
```
{% endraw %}

**All your history** starts at timestamp = 0, and ends right now.

{% raw %}
```yaml
    start: '{{ 0 }}'
    end: '{{ now() }}'
```
{% endraw %}

<p class='note'>
  The `/dev-template` page of your home-assistant UI can help you check if the values for `start`, `end` or `duration` are correct. If you want to check if your period is right, just click on your component, the `from` and `to` attributes will show the start and end of the period, nicely formatted.
</p>