---
name: "X-Up-Reload-From-Time"
area: "API"
kind: "HTTP header"
parent: "up.protocol module"
visibility: "deprecated"
url: "https://unpoly.com/api/X-Up-Reload-From-Time"
---
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# X-Up-Reload-From-Time

**This feature has been deprecated**. Read the standard [`If-Modified-Since`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-Modified-Since) request header instead. Unpoly sends it when the fragment has a [`Last-Modified`](https://unpoly.com/api/Last-Modified.md) time. See [conditional requests](https://unpoly.com/learn/conditional-requests.md).

Load [`unpoly-migrate.js`](https://unpoly.com/changes/upgrading.md) to polyfill deprecated features.

This request header contains a timestamp of an existing fragment that is being [reloaded](https://unpoly.com/api/up.reload.md).

The timestamp must be explicitly set by the user as an [`[up-time]`](https://unpoly.com/api/up-time.md) attribute on the fragment. It should indicate the time when the fragment's underlying data was last changed.

See [`[up-time]`](https://unpoly.com/api/up-time.md) for a detailed example.

## Format {#format}

The time is encoded as the number of seconds elapsed since the [Unix epoch](https://en.wikipedia.org/wiki/Unix_time).

For instance, a modification date of December 23rd 2020, 1:40:18 PM UTC would produce the following header:

```http
X-Up-Target: .unread-count
X-Up-Reload-From-Time: 1608730818
```

If no timestamp is known, Unpoly will send a value of zero (`X-Up-Reload-From-Time: 0`).