两个时间相差几天

    let aa = '2019-01-09 10:15:00'

    let bb = '2019-01-08 18:10:00'

    let start_date = moment(aa,"YYYY-MM-DD HH:mm:ss")

    let end_date = moment(bb,"YYYY-MM-DD HH:mm:ss")

    console.log('start_date=',start_date)

    console.log('end_date=',end_date)

    let days =  end_date.diff(start_date,'days')

    console.log('相差几天=',days)