IOS中能支持
YYYY/MM/DD
YYYY/M/D
YYYY-MM-DD
YYYY-MM
YYYY/MM/DD hh:mm:ss

特别注意不支持 YYYY-MM-DD hh:mm:ss

代码

    console.log('setDate-test 2019/01/01', new Date('2019/01/01')); //ok
    console.log('setDate-test 2019/1/1', new Date('2019/1/1')); //ok
    console.log('setDate-test 2019/01', new Date('2019/01')); //fail
    console.log('setDate-test 2019/1', new Date('2019/1')); //fail
    console.log('setDate-test 2019-01-01', new Date('2019-01-01')); //ok
    console.log('setDate-test 2019-1-1', new Date('2019-1-1')); //fail
    console.log('setDate-test 2019-01', new Date('2019-01')); //ok
    console.log('setDate-test 2019-1', new Date('2019-1')); //fail

实测结果