# Julia, <s>30</s> 28 bytes <!-- language-all: lang-rb --> y->(y%4<1&&y%100>0)||y%400<1 This creates an unnamed function that accepts an integer argument and returns a boolean value. To call it, give it a name, e.g. `f=y->...`. Ungolfed: function f(y) (y % 4 == 0 && y % 100 != 0) || y % 400 == 0 end Example: julia> for y in [1936, 1805, 1900, 2272, 2400] println(f(y)) end true false false true true true