On my server at least (polite Japanese rules and all that) there often is a designated "start time" by the Eorzean clock - set at least half an Eorzean hour away - being called out alongside the mark's location.

While it might not be actually considered against the game rules to ignore that announced start time, I think it could fairly be described as "early pulling" to not wait for it.

I'm not sure how it works elsewhere - do other people set times like this, or does everyone just stand there until someone decides they've waited long enough?