Chart.js/docs/docs/axes/cartesian/time.md

---
title: Time Cartesian Axis
---

The time scale is used to display times and dates. When building its ticks, it will automatically calculate the most comfortable unit base on the size of the scale.

## Date Adapters

The time scale **requires** both a date library and corresponding adapter to be present. Please choose from the [available adapters](https://github.com/chartjs/awesome#adapters).

## Data Sets

### Input Data

The x-axis data points may additionally be specified via the `t` or `x` attribute when using the time scale.

```javascript
data: [{
    x: new Date(),
    y: 1
}, {
    t: new Date(),
    y: 10
}]
```

### Date Formats

When providing data for the time scale, Chart.js supports all of the formats that Moment.js accepts. See [Moment.js docs](https://momentjs.com/docs/#/parsing/) for details.

## Configuration Options

The following options are provided by the time scale. You may also set options provided by the [common tick configuration](index.md#tick-configuration).

| Name | Type | Default | Description
| ---- | ---- | ------- | -----------
| `adapters.date` | `object` | `{}` | Options for adapter for external date library if that adapter needs or supports options
| `distribution` | `string` | `'linear'` | How data is plotted. [more...](#scale-distribution)
| `bounds` | `string` | `'data'` | Determines the scale bounds. [more...](#scale-bounds)
| `ticks.source` | `string` | `'auto'` | How ticks are generated. [more...](#ticks-source)
| `time.displayFormats` | `object` | | Sets how different time units are displayed. [more...](#display-formats)
| `time.isoWeekday` | `boolean` | `false` | If true and the unit is set to 'week', then the first day of the week will be Monday. Otherwise, it will be Sunday.
| `time.parser` | <code>string&#124;function</code> | | Custom parser for dates. [more...](#parser)
| `time.round` | `string` | `false` | If defined, dates will be rounded to the start of this unit. See [Time Units](#time-units) below for the allowed units.
| `time.tooltipFormat` | `string` | | The Moment.js format string to use for the tooltip.
| `time.unit` | `string` | `false` | If defined, will force the unit to be a certain type. See [Time Units](#time-units) section below for details.
| `time.stepSize` | `number` | `1` | The number of units between grid lines.
| `time.minUnit` | `string` | `'millisecond'` | The minimum display format to be used for a time unit.

### Time Units

The following time measurements are supported. The names can be passed as strings to the `time.unit` config option to force a certain unit.

* `'millisecond'`
* `'second'`
* `'minute'`
* `'hour'`
* `'day'`
* `'week'`
* `'month'`
* `'quarter'`
* `'year'`

For example, to create a chart with a time scale that always displayed units per month, the following config could be used.

```javascript
var chart = new Chart(ctx, {
    type: 'line',
    data: data,
    options: {
        scales: {
            x: {
                type: 'time',
                time: {
                    unit: 'month'
                }
            }
        }
    }
});
```

### Display Formats

The following display formats are used to configure how different time units are formed into strings for the axis tick marks. See [Moment.js](https://momentjs.com/docs/#/displaying/format/) for the allowable format strings.

Name | Default | Example
--- | --- | ---
`millisecond` | `'h:mm:ss.SSS a'` | `'11:20:01.123 AM'`
`second` | `'h:mm:ss a'` | `'11:20:01 AM'`
`minute` | `'h:mm a'` | `'11:20 AM'`
`hour` | `'hA'` | `'11AM'`
`day` | `'MMM D'` | `'Sep 4'`
`week` | `'ll'` | `'Sep 4 2015'`
`month` | `'MMM YYYY'` | `'Sep 2015'`
`quarter` | `'[Q]Q - YYYY'` | `'Q3 - 2015'`
`year` | `'YYYY'` | `'2015'`

For example, to set the display format for the `quarter` unit to show the month and year, the following config would be passed to the chart constructor.

```javascript
var chart = new Chart(ctx, {
    type: 'line',
    data: data,
    options: {
        scales: {
            x: {
                type: 'time',
                time: {
                    displayFormats: {
                        quarter: 'MMM YYYY'
                    }
                }
            }
        }
    }
});
```

### Scale Distribution

The `distribution` property controls the data distribution along the scale:

* `'linear'`: data are spread according to their time (distances can vary)
* `'series'`: data are spread at the same distance from each other

```javascript
var chart = new Chart(ctx, {
    type: 'line',
    data: data,
    options: {
        scales: {
            x: {
                type: 'time',
                distribution: 'series'
            }
        }
    }
});
```

When the scale is in `series` mode, the data indices are expected to be unique, sorted, and consistent across datasets.

### Scale Bounds

The `bounds` property controls the scale boundary strategy (bypassed by `min`/`max` time options).

* `'data'`: makes sure data are fully visible, labels outside are removed
* `'ticks'`: makes sure ticks are fully visible, data outside are truncated

### Ticks Source

The `ticks.source` property controls the ticks generation.

* `'auto'`: generates "optimal" ticks based on scale size and time options
* `'data'`: generates ticks from data (including labels from data `{t|x|y}` objects)
* `'labels'`: generates ticks from user given `labels` ONLY

### Parser

If this property is defined as a string, it is interpreted as a custom format to be used by Moment.js to parse the date.

If this is a function, it must return a Moment.js object given the appropriate data value.

### Internal data format

Internally time scale uses milliseconds since epoch