Tomorrow is the feast of St. Bartholomew the apostle. Bartholomew of the synoptic gospels is identified with "Nathanael" of St. John's gospel, for several reasons, as explained in this article.
It seems that "bartolomew" is derived from "bar-tholmai", or "son of Tholmai". So it is thought that his full name was Nathanael bar Tholmai. Just as St. Peter was originally Simon bar Jonah.
Bartholomew is the one who said "Can anything good come from Nazareth?" and was won over to Jesus when the Lord mentioned the fig tree that Bart had been sitting under.
Since this feast is on a Saturday this year, it's office gets cut short after daytime prayer. Evening prayer tomorrow belongs to the 21st Sunday in ordinary time. Sundays always trump feasts with the exception of feasts of Our Lord, e.g. Transfiguration, Presentation, etc.
So, do we say Evening Prayer I for St. Bartholomew tonight? The answer is no.
But, but, Daria! ---there's an Evening Prayer I for the Common of Apostles! What's that for?
It's for those places where a feast has been elevated by a diocese or religious order to a solemnity. So if a diocese were under the patronage of St. Bartholomew, and/or had a St. Bartholomew's cathedral, or if there exists a religious order of Nathanaelites, then tomorrow's feast might be celebrated as a solemnity, and those involved would do Evening Prayer one tonight, as well as EP II tomorrow evening. But if it were only celebrated as a patronal feast, the evening prayer II would be dropped in favor of evening prayer I of Sunday,since ordinary Sundays take precedence over everything except solemnities, and feasts of Our Lord.
It's complicated.
That being said, take a look at this passage from the General Instruction of the Liturgy of the Hours:
252. Everyone should be concerned to respect the complete cycle of the four-week psalter. [7] Still, for spiritual or pastoral advantage, the psalms appointed for a particular day may be replaced with others from the same hour of a different day. There are also circumstances occasionally arising when it is permissible to choose suitable psalms and other texts in the way done for a votive office.
What this seems to me to be saying is that even though Bartholomew's feast is not a solemnity in your diocese, you could, on an ordinary time weekday, appropriately choose Evening prayer I from the Common of Apostles if, say, you had a great devotion to St. Bartholomew, or your name is Bartholomew.
Or Nathanael.
