Counting specific words

Question

I want to count how many times in a column certain words from a predefined set appear. In this example those specific words will be days of the week. For example:

     Mon        =3
     Tues 
     Sun
     blank
     blank

The column has five entries, three of which are the ones I want to count.

Does anyone know the formula for achieving this in Google Spreadsheets?

Answer 1

ASSUMING
the weekdays will always be abbreviated exactly as shown,
are the entire cell content (not part of a longer string) and
data is in ColumnA,

the following may serve:

=ArrayFormula(sum(countif(A:A,{"Mon","Tues","Wed","Sun"})))  

with the insertion of other search strings to suit.