Discussion on answer by Jorge Córdoba: Made a bad code change that introduced a bug into our system. How do I rebound?

An important thing to consider is not just how it happened, but when the bug started to manifest - it's worth ruling out that the bug was missed, and it was always there, if the logs show that, for example, Daylight Savings Time was the root cause behind why the bug manifests now, but didn't at dev or testing time. Not all bugs are non-subtle "Guaranteed Path" bugs as well.