Every so often you get a case that needs to be filed on the last day of the one-year priority period. However, when this happens you need to know how long a year is.
“FOOL!” You may shout.
But no, does a one-year period include or exclude a day of a starting event? I.e. if you file a first application on 1 January 2013, do you have until 1 January 2014 INCLUSIVE to file a priority-claiming application? Or must the priority-claiming application be filed BY 1 January 2014 EXCLUSIVE, i.e. by 31 December 2013? Trainees may stumble here.
Confusingly the patent legislation in Europe and UK is not entirely helpful. To get an answer you need to go old skool: back to 1883 and the Paris Convention for the Protection of Intellectual Property.
More precisely, Article 4, paragraph C, clause 2 averts your crisis:
(1) The periods of priority referred to above shall be twelve months for patents and utility models, and six months for industrial designs and trademarks.
(2) These periods shall start from the date of filing of the first application; the day of filing shall not be included in the period.
Hurray! We can file on 1 January 2014.