# Getting started with temporal filtering

## Introducing temporal filtering 

Temporal filtering allows you to order a one-off snapshot of data from the OS NGD from a current or past date.

Temporal filtering is an optional step when you create a new data package against one of your existing recipes. For further information and step-by-step instructions on creating recipes and data packages, please see the [Getting started with recipes](https://docs.os.uk/osngd/getting-started/downloading-with-os-select+build/getting-started-with-recipes) and [Getting started with data packages](https://docs.os.uk/osngd/getting-started/downloading-with-os-select+build/getting-started-with-data-packages) pages.

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## Things to note

* You cannot apply a temporal filter to an existing data package held in your Data packages list; a temporal filter can only be added to new data packages during the data package creation stage.
* The earliest date you can request for the majority of feature types in the OS NGD via a temporal filter is 29 September 2022.
* As new feature types are added to the OS NGD, their temporal filter range will begin on the date they are added (for example, 28 March 2023 for the Waterbody Catchment Feature Type). Each feature type page states the earliest start date available for temporal filtering on that feature type. 
* If you request a temporal filter date for your new data package that precedes the date a feature type in the data package was added to the OS NGD, then no results will be returned. 
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### How do I add a temporal filter to a new data package? 

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YouTube video showing how to add a temporal filter to a new data package in OS Select+Build.
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To create a new OS NGD data package and apply a temporal filter to it:&#x20;

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#### Log into your [OS Data Hub](https://osdatahub.os.uk/) account

Click *Login* on the OS Data Hub menu bar to log into your account.

<figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2F1Gd3vBvSOqXLYTPpZsO9%2Fimage.png?alt=media&#x26;token=afd47dd4-6005-4d33-a8ef-ec6540a138fb" alt="A screenshot of the OS Data Hub home page showing the sign up and log in buttons in the top right hand corner" width="563"><figcaption><p>Screenshot showing the OS Data Hub homepage.</p></figcaption></figure>
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#### Navigate to the OS Data Hub workspace

Select *Data* from the menu bar to view your workspace.
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#### Navigate to the OS *Select+Build Recipe Library*

Choose *Downloads* > *OS Select+Build Recipe Library* from the left hand side secondary navigation menu. You will then be taken to your organisation's OS Select+Build Recipe Library.
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#### Find the recipe you want to create a data package against

In your OS NGD Select+Build Recipe Library, scroll or search for the recipe you wish to create a data package against, select that recipe, then click the *Add data package* button.

<figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2FamiHxVEA8ivdYWmhdcR0%2FScreenshot%20Recipe%20Library.png?alt=media&#x26;token=1bd9e5df-cb7d-45c5-8f08-3c1ab13b25f1" alt="Screenshot of the OS Select+Build Recipe Library screen in the OS Data Hub."><figcaption><p>Screenshot of the OS Select+Build Recipe Library screen in the OS Data Hub.</p></figcaption></figure>
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#### Add details to the data package

<figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2Ft2fL7lfmxkIycgc9TeBT%2FScreenshot%20Create%20data%20package.png?alt=media&#x26;token=4caad2a6-87b5-423b-a3af-53fb9f40927f" alt="Screenshot showing an example of adding a data package to a recipe using OS Select+Build in the OS Data Hub."><figcaption><p>Screenshot showing an example of adding a data package to a recipe using OS Select+Build in the OS Data Hub.</p></figcaption></figure>

Add the following details to your data package under *Add a data package* in the secondary navigation menu:

* Give your data package a name.
* Choose the area you want to receive your data for: either 'All of Britain or Predefined Area' (this means you receive data and it will not be refined by location) or 'Draw a polygon / upload a file / use an OS polygon' (to select a smaller area for your data to be provided for).
* Select the desired [coordinate reference system](https://docs.os.uk/osngd/getting-started/os-ngd-fundamentals/coordinate-reference-systems).
* Select a file format: [CSV](https://docs.os.uk/osngd/os-ngd-fundamentals/file-formats-and-naming#csv-overview) or [GeoPackage](https://docs.os.uk/osngd/os-ngd-fundamentals/file-formats-and-naming#geopackage-overview).
* Select the updates you want. Instead of selecting the 'not required' or COU (Change-Only Update) frequency options (which are available under the 'Select updates' drop-down), to **apply a temporal filter**, you should select the option for a one-off snapshot of a current or past date by ticking the following check box:

<div align="center"><figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2FPGGVOm5Q8goQMpGIOYDU%2FTemporal-checkbox.PNG?alt=media&#x26;token=491bdf54-febf-4aeb-8db8-d6203527c638" alt="Screenshot showing the one-off snapshot check box option when creating a new data package in OS Select+Build in the OS Data Hub."><figcaption><p>Screenshot showing the one-off snapshot option when creating a new data package in OS Select+Build.</p></figcaption></figure></div>

* Select the supply date needed for the snapshot:

<div align="center"><figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2F9oqtUCaIeSskobxNgta8%2FTemporal-checkbox2.PNG?alt=media&#x26;token=f2c6a1a6-486c-41a1-b404-b614191d9d2b" alt="Screenshot of OS Select+Build during the new data package creating stage showing the one-off snapshot check box option selected and a date selected."><figcaption><p>Screenshot of OS Select+Build showing the one-off snapshot check box option selected and a date selected.</p></figcaption></figure></div>
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#### Finish creating your data package

Click the *Create data package* button.
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You will receive an email confirming that your data package is being created and another one when your new data package is ready to download.
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