Adding date to December 7, 2020 do not render html in _site

[Hemant Patwal]

When i use date as 2019-12-7-Hello-World.md it renders a folder Hello-World in _site.
However if i use date as 2020-12-7 it fails to render the Hello-World in _site.

From logs seems its working fine, but i don't get html in later case

      Regenerating: 2 file(s) changed at 2020-12-06 23:56:29
                    _posts/2020-12-7-Hello-World.md
                    _posts/12-7-2020-Hello-World.md
       Jekyll Feed: Generating feed for posts
                    ...done in 0.074205 seconds.
                    
      Regenerating: 2 file(s) changed at 2020-12-06 23:56:56
                    _posts/2019-12-7-Hello-World.md
                    _posts/2020-12-7-Hello-World.md
       Jekyll Feed: Generating feed for posts
                    ...done in 0.078577 seconds.