You are probably well familiar by now with how English forms 'tag questions' ( ... aren't you? ... ), but here is your chance to practise examples in other timescales and tenses.
Don't forget that ~ unusually ~ English makes rather more of a brief grammatical fuss than many other languages do over this everyday structure: we need to switch between an affirmative sentence and negative tag (or vice-versa), carry the subject agreement right through the sentence ('He has, hasn't he?'), and even put in a 'stopgap auxiliary', usually in the form of 'do' ('It arrives automatically, doesn't it?') if there happens not to be one already available.
With this in mind, let's hope your own Answers will indeed 'be OK'!
(The 'other reason' being that the three elements in the date ~ 5, 12, 13 (in the order that British people would write the date; not that matters for present purposes) ~ are a 'Pythagorean triple'. You may remember that the simplest right-angled triangle with whole-numbered side lengths is the '3,4,5 triangle' (since 3 x 3 = 9, 4 x 4 = 16, and the sum of those two numbers is 25 which is 5 x 5); the next one that works so tidily is 5,12,13 (whose mathematical 'squares' are 25 again, + 144 = 169).)