This might seem like a small thing, but it’s all about doing what’s best for your website’s visitors, not what’s easiest for you:
- 12 am & 12 pm do not technically exist: yes, this might seem pedantic, but it won’t if people show up 12 hours early or late for an event.
The details don’t really matter — they’re related to Latin and astronomy. The point is that people get them confused, so “12 am” & “12 pm” should be avoided.
Don’t offload effort onto your website visitors — be as unambiguous as possible: noon & midnight should be preferred, because they’re impossible to get confused.