In general, when booking your flight to Dhaka, October is the cheapest month on average.
Most flyers found that booking flight tickets 50 days in advance of their planned departure date is, on average, the best time to get cheap flights to Dhaka.
On average, the cheapest flights to Dhaka are found when departing on a Monday. Try to avoid departing on a Saturday, as this is usually the most expensive day.
On average you can find the best deals on plane tickets to Dhaka when looking for flights with midday departure times.