Hasta entonces

[poli]

I know it means until that time. Can it be used like hasta luego?

[Rusty]

'Entonces' is an established time; 'luego' isn't.

It's the difference between 'see you then' and 'see you later' in English.

[AngelicaDeAlquezar]

I agree with Rusty. Although both expressions may be used for saying goodbye, "hasta entonces" needs a specific situation or time reference expressed right before being used.