Bar chart / time steps

I am working on a kibana canvas dashboard and i am using a bar chart to display weekly costs.
On X-axis : time ...... I was wondering if it's possible to change time steps : the data is shown correctly, but in the x-axis i only want to show dates every 7 days, but what i am getting is dates every 3 days .

for example i dont want May 19, May 25, May 31 ..... to be displayed
Thank you in advance