Dfyjkt

I'm planning to visit Indonesia, holding a passport that gives me visa-free access for 30 days (just like over 160 countries get).

From Wikitravel, there is a part that reads:

Also note that the days a visa holder is within Indonesia are counted
with the day of entry being day 1, not day 0. This means that by 24:00
(twelve midnight) on the night of the day of arrival you have been in
Indonesia for one day. If you enter at 23:59 (11:59pm) then 2 minutes
later you have been in Indonesia for 2 days.

Immigration officials may claim that a 30-day visa-on-arrival means
that you must leave before 30-days (ie on the 29th day or before). Be
careful about this.

My travel dates are as follows:

Arrival: May 9 (around 10AM).
Departure: June 7 (around 2PM) at a different airport.

Including May 9 and June 7, I would have stayed in Indonesia for exactly 30 days.

In my last visit, I have a visa-exception stamp that reads:

Permitted to enter and stay for 30 days from date shown above

I have doubts about the above Wikitravel quoted paragraph, about the part that says I must exist the country on the 29th day.

I would appreciate if any of you have experience with this. I'm not going to risk an over stay or an entry-refusal, and I have the option to arrive on May 10 or later. From my experience, a 30 days visa means I can stay 30 days, so I shouldn't probably spend a considerable amount money to purchase a new ticket (they are separate tickets, and cost works out cheaper to buy a new one).

Is there any chance that I will be denied entry or marked an overstay with this, specially considering how the immigration process in Indonesia? I have asked a similar question about a Schengen visa in the past. I was given a 20 day visa, and I exited on the 20th day, with no issues at all.

Thanks everyone in advance.

You are fine entering on 9 May and leaving 7 June, that is exactly 30 days including the arrival and departure date. What Wikitravel is trying to make clear here (in the first paragraph) is that both the arrival and the departure date are counted as one of your 30 days. The second paragraph I suspect was added by someone who didn't understand the first one, and tried to stay 31 days.

What many people do is to "add 30" to their arrival date- if you "add 30" to 9 May, you would get 8 June- but this is because it is not counting 9 May as the first day, which is a common mistake travellers make when calculating their permission to stay. Your first day counts as one day, so you have how many days in addition to your first day? 29. But adding 29 to 1 = 30 days spent in country. Makes sense?

To explain in another way- say you enter on a Monday. Add seven days to Monday, and you get the following Monday, when you leave. How many days were you there? 8, including both Mondays- NOT 7.

This is pretty much a universal rule everywhere, it is not in any way specific to Indonesia. It's really more an issue of mathematics or counting than anything to do with travel or visas, but it is a very common misunderstanding. But FWIW I have visited Indonesia on a 30-day visa free exemption and stayed exactly 30 days as you propose and there was no issue.