There is a concept of ‘rubber time’ in Indonesia, and many social events are not expected to start punctually, however when it comes to business situations, it will likely be expected for expats to arrive on time. With this and other aspects of work-related social interactions, it’s best to know both what is expected of you as a foreigner, and what cultural customs you should be aware of.
Entry into the meeting room may sometimes be according to rank, and meetings earlier on can be more about getting to know each other than about the business itself - time doesn’t necessarily mean money. Don’t cross the line between bargaining and putting pressure on someone; bear in mind the culture of wanting to avoid disagreements, read into the answers you are given and remember the virtue that is patience, as some agreements will take longer to complete than you may be used to.