Validity dates

Validity dates show when tariff elements, such as measures, are live.

Most elements use a pair of validity dates. The element is live between the validity start date and validity end date.

If the validity end date is blank the element is live forever.

Validity dates can be changed after a tariff element is created. End dates can be added if they were not specified before and existing dates can be updated.

Validity start and end dates are inclusive. This means the element is live from the beginning of the start date to the end of the end date.

An element with the same start and end date is live for one day.

Ending validity of measures

There are 4 ways to end-date a measure:

1. The measure is given an explicit end date on the measure record itself
2. The measure’s generating regulation is a base regulation, and the base regulation itself is end-dated
3. The measure’s generating regulation is a modification regulation, and the modification regulation itself is end-dated
4. The measure’s generating regulation is a base regulation, and any of the modification regulations that modify it are end-dated
5. The measure’s generating regulation is a modification regulation, and the base regulation that it modifies is end-dated

In the UK Tariff, we do not use regulation end dates. Validity end dates are added to the measure explicitly (as per point 1).

Validity dates on descriptions

Footnotes, certificates, additional codes and geographical areas all have descriptions which can change over time. There must always be only one description valid at any time.

For this reason, descriptions do not have end dates and only have a start date. The description is live until the start date of the next description, or indefinitely if there are future descriptions.