In general when looking for the cheapest flight to Indonesia, try to book your flight during the month of March for the best deal.
On average, from most locations, when planning your trip to Indonesia, try to book your flight in the region of 60 days in advance for the cheapest prices.
Most of our users find that booking their departure to Indonesia on a Monday is the cheapest. Conversely, departing on a Saturday seems to be the most expensive.
On average you can find the best deals on plane tickets to Indonesia when looking for flights with afternoon departure times.