Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Ho Chi Minh City to Cadiz as you normally would.
For a flight from Ho Chi Minh City to Cadiz, you will be flying from Ho Chi Minh City. Ho Chi Minh City (SGN) is just 7.3 km from the center of the city. Ho Chi Minh City is the only Ho Chi Minh City airport and it handles 0 outbound flights to Cadiz per day. 0 airlines have flights to Cadiz from Ho Chi Minh City on a regular basis.