With the following model:

class Model {
 public Instant time;
}

The serialized time saved in Arango is in server-local timezone. So, when using it in a query, i.e. x.time < DATE_NOW() isn't predictable, since x.time is in server-local time, whereas DATE_NOW() is in UTC.

Not sure if this is a feature request serialize Instants in UTC, or a bug.