# HTML <ins> datetime Attribute
The `datetime` attribute of the `
` tag is used to specify the exact date and time when text was inserted or added to a document.
While this attribute does not change the visual appearance of the inserted text in standard web browsers, it provides valuable machine-readable metadata. This metadata can be utilized by search engines, web crawlers, version control systems, and assistive technologies (such as screen readers).
---
## Syntax
```html
Inserted text
```
---
## Attribute Values
The `datetime` attribute value must be a valid date and time string. The format is broken down as follows:
| Value Component | Description | Example |
| :--- | :--- | :--- |
| **`YYYY`** | Four-digit year | `2023` |
| **`MM`** | Two-digit month (01 to 12) | `10` (October) |
| **`DD`** | Two-digit day of the month (01 to 31) | `25` |
| **`T`** | Literal separator indicating the start of the time component (Required) | `T` |
| **`hh`** | Two-digit hour in 24-hour format (00 to 23) | `14` (2:00 PM) |
| **`mm`** | Two-digit minutes (00 to 59) | `30` |
| **`ss`** | Two-digit seconds (00 to 59) | `00` |
| **`TZD`** | Time Zone Designator (e.g., `Z` for UTC/Zulu time, or `+hh:mm` / `-hh:mm` for local offsets) | `Z` or `+08:00` |
---
## Code Examples
### Basic Example
In this example, we mark a piece of text as inserted and specify the exact UTC date and time of the modification:
```html
We have updated our subscription model.
The monthly fee is now $9.99.
```
### Example with Local Time Zone Offset
If you want to specify a local time zone instead of UTC (Zulu time), you can use a time zone offset:
```html
The conference schedule has been finalized.
The opening keynote starts at 9:00 AM EST.
```
---
## Browser Support and Behavior
| Feature | Chrome | Edge | Firefox | Safari | Opera |
| :--- | :---: | :---: | :---: | :---: | :---: |
| **`datetime` Attribute** | Yes | Yes | Yes | Yes | Yes |
* **Visual Rendering:** Browsers do not render the `datetime` attribute visually. By default, browsers will only apply an underline to the content inside the `` tag.
* **Accessibility:** Screen readers and other assistive technologies can read this attribute to inform users when a specific edit or addition was made to the document.
* **SEO & Web Scraping:** Search engines and document parsers use this attribute to track document history and content updates.
---
## HTML 4.01 vs. HTML5
There are no functional differences for this attribute between HTML 4.01 and HTML5. It remains the standard way to define the insertion timestamp for the `` element.
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