Is there a chance to sort groups by condition?

My problem:

<xpath expr="//filter[@string='Type']" position="after">                    
   <filter string="Days" name="days_group" domain="[]" context="{'group_by':'date:day'}"/>
   <filter string="Months" name="days_group" domain="[]" context="{'group_by':'date:month'}"/>
</xpath>

Grouped records are in descending order which is ok for me but i want to sort groups in the same way.