var ut = Math.floor((new Date()).getTime()/1000); var week = Math.floor(ut / 60 / 60 / 24 / 7); var year = Math.floor(ut / 60 / 60 / 24 / 365); console.log(week); if(week % 2 == 1) { console.log('奇数週'); } else { console.log('偶数週') }