Flutter give container rounded border

I'm making a Container(), I gave it a border, but it would be nice to have rounded borders.

This is what I have now:

Container(
      width: screenWidth / 7,
      decoration: BoxDecoration(
        border: Border.all(
          color: Colors.red[500],
        ),
      ),
      child: Padding(
        padding: EdgeInsets.all(5.0),
        child: Column(
          children: <Widget>[
            Text(
              '6',
              style: TextStyle(
                  color: Colors.red[500],
                  fontSize: 25),
            ),
            Text(
             'sep',
              style: TextStyle(
                  color: Colors.red[500]),
            )
          ],
        ),
      ),
    );

I tried putting ClipRRect on it, but that crops the border away. Is there a solution for this?

Try using the property borderRadius from BoxDecoration

Something like

Container(
  decoration: BoxDecoration(
    border: Border.all(
      color: Colors.red[500],
    ),
    borderRadius: BorderRadius.all(Radius.circular(20))
  ),
  child: ...
)

To make it completely circle:

Container(
      decoration: BoxDecoration(
        shape: BoxShape.circle,
      ),
    )

To make it a circle at selected spots:

Container(
      decoration: BoxDecoration(
        borderRadius: BorderRadius.only(
            topRight: Radius.circular(40.0),
            bottomRight: Radius.circular(40.0),
            topLeft: Radius.circular(40.0),
            bottomLeft: Radius.circular(40.0)),
      ),
      child: Text("hello"),
    ),

or

  Container(
      decoration: BoxDecoration(
        borderRadius: BorderRadius.all(Radius.circular(20)),
      ),
      child: ...
    )