message: Make day labels to be a Typography, closes
diff: @@ -2,6 +2,7 @@ import * as React from 'react';
  import * as PropTypes from 'prop-types';
  import clsx from 'clsx';
  import IconButton from '@material-ui/core/IconButton';
  +import Typography from '@material-ui/core/Typography';
  import createStyles from '@material-ui/styles/createStyles';
  import withStyles, { WithStyles } from '@material-ui/styles/withStyles';
  import { Theme } from '@material-ui/core';
  @@ -44,7 +45,9 @@ class Day extends React.PureComponent<DayProps> {
  return (
  <IconButton className={className} tabIndex={hidden || disabled ? -1 : 0} {...other}>
  + <Typography variant="body1" color="inherit">
  {children}
  + </Typography>
  </IconButton>
  );
  }
  