Wice Grid - How to customize a SQL-query?

Hello guys,

is it possible to “customize” filter specific SQL-queries? Maybe in the
wice_grid_config.rb ?

If so then tell me how please.

To mention the problem i have, here it comes:

I want to filter some records of a specific table, let say the name of
the table is clients.

The filter i want to use is the date->to filter.
The problem is that if I use it, let say for the date “02.04.2015” then
it will look for all dates “< 02.04.2015”.

But i want it to be “<= 02.04.2015”.