src/main/java/org/efaps/ui/wicket/models/objects/grid/UIGrid.java
public boolean isDateFilter(final IFilter _filter) throws EFapsException
    {
        final boolean ret;
        final Field field = Field.get(_filter.getFieldId());
        // Explicitly set UIProvider
        if (field.getUIProvider() != null && (field.getUIProvider() instanceof DateTimeUI || field
                        .getUIProvider() instanceof DateUI)) {
            ret = true;
        } else {
            final Attribute attr = getType().getAttribute(field.getAttribute());
            if (attr == null) {
                ret = false;
            } else {
                final IUIProvider uiProvider = attr.getAttributeType().getUIProvider();
                ret = uiProvider instanceof DateTimeUI || uiProvider instanceof DateUI;
            }
        }
        return ret;
    }
public boolean isDateFilter(final IFilter _filter) throws EFapsException
    {
        final boolean ret;
        final Field field = Field.get(_filter.getFieldId());
        // Explicitly set UIProvider
        if (field.getUIProvider() != null && (field.getUIProvider() instanceof DateTimeUI || field
                        .getUIProvider() instanceof DateUI)) {
            ret = true;
        } else {
            final Attribute attr = getType().getAttribute(field.getAttribute());
            if (attr == null) {
                ret = false;
            } else {
                final IUIProvider uiProvider = attr.getAttributeType().getUIProvider();
                ret = uiProvider instanceof DateTimeUI || uiProvider instanceof DateUI;
            }
        }
        return ret;
    }
Checks if is date filter.

@param _filter the filter
@return true, if is date filter
@throws EFapsException the e faps exception