How to select multiple dates with SQL

I Need to select Data from Tables of a specific user at certain days. I am not exactly sure what is wrong with my code.

Here is my code:

select k.info, z.mes_user, z.mes_date, m.val_user, m.val_date
from table_K k
left join table_M m on k.key1 = m.key1
left join table_Z z on m.key1 = z.key1 and m.key2 = z.key2
where (m.val_user like '%Username%' or z.mes_user like '%User-ID%') and
(
z.mes_date like '%18.04.17%' or
z.mes_date like '%20.04.17%' or
m.val_date like '%18.04.17%' or
m.val_date like '%20.04.17%');

The mistake is propably in the where clause.

'Username' and 'User-ID' are just placeholders for the code. The data type of mes_date and val_date are date.