Description

Using dateFormat D in a Gantt chart still shows the full month and year.

Steps to reproduce

gantt
    title Test
    dateFormat D
    A :a, 1, 1d

Screenshots

Code Sample

gantt
    title Test
    dateFormat D
    A :a, 1, 1d

Setup

• Mermaid version: v11.6.0
• Browser and Version: Chrome

Suggested Solutions

Should show only the day, not the year and month.

Additional Context

What I actually want is a dateFormat none or dateFormat T where I don't actually use concrete days but an abstract time sequence of time step T. I was planning on just formatting it as D and then setting everything to 0000-01-01 as the start point and then go up from there.