When flying from Darwin to Reykjavik, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
Darwin (DRW) is the airport you will fly out of if you book a flight from Darwin to Reykjavik. You should not have trouble finding flights to Reykjavik from Darwin; the airport handles an average of 0 outbound flights to Reykjavik per day. You should also have plenty of airline options to choose from since 0 airlines have flights from the Darwin airport to Reykjavik. It is only a 6.4 km journey to Darwin (DRW) from Darwin’s city centre.