function isThatDay ( ) { return Date . now ( ) >= 1563375600000 && Date . now ( ) <= 1563721200000 ; } export default function prayForKyoani ( ) { const extraCss = document . querySelector ( '#extraCss' ) ; setTimeout ( ( ) => { if ( isThatDay ( ) ) { extraCss [ 'href' ] = './extra/prayForKyoani/style.css' ; } } , 0 ) ; }