This help book in the Language Reference book covers the following information:

dBASE Plus 8 supports two types of dates:

A primitive date that is compatible with earlier versions of dBASE

A JavaScript-compatible Date object.

A Date object represents a moment in time. It is stored as the number of milliseconds since January 1, 1970 00:00:00 GMT (Greenwich Mean Time). Although GMT and UTC (a compromise between the English and French acronyms for Universal Coordinated Time) are derived differently, they are considered to represent the same time.

Modern operating systems have their own current time zone setting, which is used when handling Date objects.  For example, two computers with different time zone settings—whether or not they are physically in different time zones—will display the same time differently.