For example, in interpreting an EU measure it may be relevant to look at its aim and content, as revealed by its legal basis as found in the treaties. In interpreting workers’ annual leave entitlement, the legal basis of the Working Time Directive was found to be relevant. ⁵  The court found that member states could not adopt national rules under which workers’ rights to paid annual leave depended on their having completed a minimum period of employment with the same employer. Had the court not looked to original treaty provisions giving rise to the Working Time Directive, it may have given the directive an alternative meaning. Once we have left the EU, our courts will continue to be able to look to the treaty provisions in interpreting EU laws that are preserved.