Question: why is 12 pm before 1pm?
Answer: The 12-hour clock is a time convention in which the 24 hours of the day are divided into two periods: a.m. (from the Latin, ante meridiem, meaning before midday) and p.m. (post meridiem, meaning past midday). ... Since noon is neither before noon nor after noon, a designation of either a.m. or p.m. is incorrect.