毎日運行って英語でなんて言うの？

You have flown to Barcelona a few times and you notice that there is one at the same time every day from that airport.
It seems to be a regular daily flight.

"Excuse me, how often are their flights to Barcelona from here?"
"This flight goes every day."
"Does that include weekends?"
"Yes, You can take a plane to Barcelona any day."

In order to explain that a certain flight route flies everyday, you can say:

This flight route operates every day.
Flight route - This is the pathway taken by a plane. For example from London to Amsterdam to South Africa.
Operates - runs or functions.
Everyday - daily

You can also say:
This flight route operates on a daily basis.
Daily basis - Everyday. To add basis is to emphasize that it runs everyday.

I hope that helps!

>The flight to "Tokyo" is available 7 days a week.
●
Available=able to be used or obtained
7 days a week = This means everyday because there are only 7 days in a week.
.................
This sentence clearly indicates that the flight to "Tokyo"happens every day.

"On a daily basis" happening each and every day...
Some flight routes are so popular that they run on a dialy basis...
These are normally domestic flights...and indeed many business people use short haul flights like buses;-)
Hopping on to a flight that runs as "regular as clockwork" (idiom)

Whhen you are wanting to say something happens or is done every day you can say 'every day', 'daily' or 'on a daily basis' these all mean the same thing
Operates means that it runs/happens
Flight route is the plan which a plane journey takes (london to paris)

Operates daily.
Flies daily.
Daily flight path.

The flight from Boston to Kentucky operates daily.
The plane flies daily.
Your destination is on a daily flight path.