Safari returns incorrect value for Date toISOString()

I found the problem. Safari is unable to convert a date string in the format 2019-12-01T10:10:10 into a Date object without screwing with it. The solution (found here) is to reformat to 2019/12/01 10:10:10 which is supported by all browsers.

// convert into YYYY/MM/DD HH:MM:SS
var dateString = '2019-12-01T10:10:10'.replace(/-/g, '/').replace('T', ' ');

Safari (correct):

new Date(dateString).toISOString()
// returns 2019-12-01T09:10:10.000Z

Chrome (correct):

new Date(dateString).toISOString()
// returns 2019-12-01T09:10:10.000Z

FireFox (correct):

new Date(dateString).toISOString()
// returns 2019-12-01T09:10:10.000Z

Hope this saves the next frustrated developer a couple of hours!

It looks like Safari takes the provided input time as the time in UTC, but Chrome and Firefox are using the local time zones. I could not find any official document supporting this behaviour. But you can easily verify it from your browser. Here are outputs for me in India (GMT+530).

Chrome/FF:
new Date('2019-12-01T10:10:10Z').toISOString()
"2019-12-01T10:10:10.000Z"
new Date('2019-12-01T10:10:10').toISOString()
"2019-12-01T04:40:10.000Z"

Safari:
new Date('2019-12-01T10:10:10').toISOString()
"2019-12-01T10:10:10.000Z"
new Date('2019-12-01T10:10:10Z').toISOString()
"2019-12-01T10:10:10.000Z"