For example, when I pass a full date & time string to Date()
new Date('2020-01-01 00:00:00').toISOString()
// '2019-12-31T17:00:00.000Z'
it treats the input as local time.
However, when I pass just a date string
new Date('2020-01-01').toISOString()
// '2020-01-01T00:00:00.000Z'
it treats the input as UTC time.
Why is this behavior the default?