5:30pm Ceremony - Afternoon or Evening?

Definitely evening. I would say "at half past five in the evening"

Evening is defined as 6pm to bedtime.

I would say "at five-thirty in the afternoon".

Mine say "five o'clock in the evening"

So I vote evening

Yeah I think I would consider that "half past five in the afternoon". Or "at five-thirty in the afternoon" if it's more informal.

If you want to go by Emily Post, it would be half after five. It is most definitely in the afternoon, but apparently that is not necessary.

http://www.emilypost.com/weddings/wedding-invitations-and-announcements/335-wording-formal-wedding-invitations

Def afternoon. I like the "half past five in the afternoon"

I used afternoon on my invites for my 5 pm ceremony, so I'd say half past five or half past five in the afternoon.