This line of code checks whether the minute is prime when deciding whether to display an easter egg:
for (int i = 2; i < 63; i++) if (ct.minute() != i && ct.minute() % i == 0) return;
However, this erroneously includes 1 as a prime number, when it is not prime.
who cares ?
You could consider it a double easter egg.
At first it seems to happen on prime minutes, but then you see - easter egg - it happens on 1 too