Feature Request for Disable Days offset

Hi,

your plugin is just awesome. I need the datepicker field and i have seen that you support “Disable Dates” and “Disable Days”
I would like to ask if it´s possible to use a Disable Days offset.
Which means for example i can configure a “Disable Days offset” of +3. This would mean that it is only possible to select dates 3 days from now.

Further i would like to ask if it is possible to disable specific dates by using the administration frontend in order to prevent users can select it.

Btw. for such a great plugin i would be willing to donate! Keep it up!

For the “Disable Days offset” i took a first step.
I added possibility for configuring the field on the admin by adding the following code to
wp-content\plugins\wc-fields-factory\classes\fields\wcff-datepicker.php

		<tr>
			<td class="summary">
				<label for="post_type"><?php _e( 'Disable Days Offset', 'wc-fields-factory' ); ?></label>
				<p class="description"><?php _e( 'You can configure a “Disable Days offset”. For example (+3) would mean that it is only possible to select dates 3 days from now.', 'wc-fields-factory' ); ?></p>
			</td>
			<td>
				<div class="wcff-field-types-meta" data-type="text" data-param="disable_days_offset">					
					<input type="text" name="wcff-field-type-meta-disable_days_offset" id="wcff-field-type-meta-disable_days_offset" placeholder="-10:+10"/>						
				</div>
			</td>
		</tr>

The value is persisted.
What steps should i take next to apply the effect to the frontend?

Best Regards
Chris