Make-date migration

1

Can anybody please give me the golden tip on how to make a ‘date’ from ‘date-time’ in the migration?

‘Occurred’: number ‘date’
'Created At: number ‘date-time’

'Notes': collection = <!"Default collection mapping, should succeed when key-property remains the same."!> map ( $ .'Notes'* ) as $ = (
	'Note': text = $ .'Note'
	'Occurred': number = make-date ( $ .'Created at' as $ ) // <- how to create a 'date' number?
	'Created At': number = $ .'Created At'
)
2

Hi! Division by 86400 should do the trick, possibly with an offset added first