Returns the difference in seconds between the receiver and Greenwich Mean Time (GMT) at the specified date.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
- Core Foundation
The time zone to analyze.
The date at which the interval is to be computed.
The difference in seconds between
tz and GMT at the specified date,