Using Instant/ChronoUnit to get the time in nanos-since-epoch at midnight today is 24 hours ahead of using GregorianCalendar/Date

Question

I\'m attempting to get today\'s date in nanos since Epoch at midnight (e.g. 13 Feb 2021 00:00:00).

Using GregorianCalendar/Date appears to get the right result.

Th