Dear @ifesdjeen, In this line, int firstFireOffset = (int) (firstDelay / resolution), firstFireOffset maybe is negative if firstDelay is so large. I think all variable around should be long, and we just need cast to int when access wheel[index]. Please review this problem. https://github.com/ifesdjeen/hashed-wheel-timer/blob/6dfa8a8c99b0df16e21c9410f31bd186cfb6b0c0/core/src/com/ifesdjeen/timer/HashedWheelTimer.java#L396 Thanks and best regards,