Why was my phones clock an hour off this morning?

[AC Question]

My alarm went off based on it and woke me up an hour early. The sun wasn't up, the dogs were still sleeping. I am exhausted and now concerned this could happen again. The date and time zone were correct. I restarted the phone and took the battery out. The issue resolved once I manually changed the time. Now the automatic time zone clock time is working. But seriously?