> For the complete documentation index, see [llms.txt](https://documentation.crossengage.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.crossengage.io/data-and-engagement-platform/messages/personalization/formatting-functions/date-formatting.md).

# Date Formatting

The computeDate function can be used to calculate a date, or to change the displayed format of the date. The syntax of this function is:

```jsx
{{computeDate '{
    "dateTrait": [User attribute], 
    "timePhrase": [Time phrase], 
    "outputFormat": [Output format]
    }'
}}
```

{% hint style="info" %}
While the computeDate function can alter how dates are displayed, the format in which dates are sent to CrossEngage must remain the same: ISO8601 format in UTC (Coordinated Universal Time). This can be written as yyyy-MM-dd.
{% endhint %}

<table data-header-hidden><thead><tr><th width="159.66666666666669">Property</th><th width="92">Type</th><th>Description</th></tr></thead><tbody><tr><td>Property</td><td>Type</td><td>Description</td></tr><tr><td><code>dateTrait</code></td><td>string</td><td><strong>Optional</strong>. The user attribute that is used for date formatting and calculations. If omitted, the value '<strong>now'</strong> is used, which takes the system time at the time of dispatch.<br>e.g user.[traits.birthday]</td></tr><tr><td><code>timePhrase</code></td><td>string</td><td><strong>Required</strong>. The operation that is executed on the <code>dateTrait</code>. If you want to use the dateTrait directly, simply set the timePhrase e.g. <code>+1 hour</code>, <code>+2 days</code>. This attribute is required even if you wish to display the current date: to do so, simply set the time phrase equal to <code>0</code> or <code>now</code>.</td></tr><tr><td>outputFormat</td><td>string</td><td><strong>Required</strong>. The format the function should output. All common date formats are supported e.g. <code>yyyy-MM-dd</code>, <code>dd/MM/yy</code>.</td></tr></tbody></table>

#### Displaying the date 10 days from a user's birthday

For this example, we output the date 10 days from the User's birthday.

```jsx
{{computeDate '{
    "dateTrait": "user.[traits.birthday]",
    "timePhrase": "+ 10 days", 
    "outputFormat": "yyyy-MM-dd"
    }'
}}
```

For example, if the User has his next birthday on 2022-01-01, it would compute the date 2022-01-11.

{% hint style="info" %}
Depending on how many characters are used, the dateformat is either single- or double digits, e.g. "yyyy-MM-dd" will result in a date with leading zeros for month and date (2022-01-11),  "y-M-d" without leading zeros (2022-1-11).&#x20;

The year is also a special case were "y", "yyy" and "yyyy" all output the full year (2022), wheras "yy" will output only the year of the century (22).
{% endhint %}

{% hint style="warning" %}
Please note that it lower-/uppercasing matters - `dd`is not the same as`DD,as`lower cased "dd" is the day of the month,  whereas "DD" is the day of they year, e.g. the 1st of February is the 32nd day of the year.
{% endhint %}

Some [examples](https://www.joda.org/joda-time/key_format.html) (for 2024-05-10 14:15:55.978):

| Symbol | Meaning                      | Example |
| ------ | ---------------------------- | ------- |
| Y/y    | year of era/year             | 2024    |
| w      | week of year                 | 19      |
| E      | day of week (text)           | Fri     |
| e      | day of week (num)            | 5       |
| d      | day of month                 | 10      |
| M      | month of year                | 5       |
| m      | minute of hour               | 15      |
| a      | halfday of day (AM/PM)       | PM      |
| K      | hour of halfday (12h format) | 2       |
| H      | hour of day (24h format)     | 14      |
| s      | second of minute             | 55      |
| S      | fraction of second           | 978     |