format functions must throw exceptions on attempt on processing invalid dates

[kossnocorp]

See JavaScript's toISOString and Intl API for the reasoning:

const date = new Date()

date.setHours('nope')
//=> NaN

date.getYear()
//=> NaN

date.toString()
//=> Invalid date

date.toISOString()
//=> RangeError: Invalid time value

new Intl.DateTimeFormat('en-US').format(date)
//=> RangeError: Invalid time value