When flying from Kuala Lumpur to Bilbao, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
For a flight from Kuala Lumpur to Bilbao, you will be flying into Bilbao. Bilbao (BIO) is just 4.9 km from the centre vof the city. Bilbao is the only Bilbao airport and it handles 0 inbound flights from Kuala Lumpur per day. 4 airlines have flights to Bilbao from Kuala Lumpur on a regular basis.
The most popular airlines flying from Kuala Lumpur to Bilbao are British Airways, KLM and Qatar Airways. Something to consider prior to booking your flight.