Hola Ingrid,
You can find mass times on the
http://www.archicompostela.org website.
Click on the colourful shell.
Then click on the English link
You will see a box that says: Services for Pilgrims
Click on St James link and then on Santiago Cathedral
There seems to be only one 10:30 mass so perhaps that is the only Vigil mass.
PS: On the same site you can get the times that the Botafumeiro will be used at mass:
(Sometimes tour groups pay for it to be used at other times).
Lord's Epiphany on January 6
Easter Sunday of Easter
Ascension of the Lord 40 days after Easter
Feast of the emergence of the Apostle on May 23
Pentecost 50 days after Easter
Martyrdom of the Apostle Santiago on July 25
Assumption of the Virgin Mary on August 15
All Saints' Day on November 1
Christ the King 5th Sunday before Christmas
Immaculate Conception on December 8
Nativity of Our Lord on December 25
Translating the remains of the Apostle December 30