# plus method

ZonedDateTime plus(

1. Duration duration

)

Adds the specified Duration to this date-time.

The operation is timezone-aware and handles daylight saving time transitions correctly. If the addition crosses a DST boundary, the offset may change.

Example:

    final zdt = ZonedDateTime.parse('2023-03-11T01:30:00-05:00[America/New_York]');
    final later = zdt.plus(Duration(hours: 2));

    // This crosses the DST transition (spring forward)
    print('Before: $zdt'); // 01:30 EST
    print('After: $later');  // 04:30 EDT (skips 02:30-03:30)

## Implementation

    ZonedDateTime plus(Duration duration) {
      final newLocalDateTime = _localDateTime.plus(duration);
      return ZonedDateTime.of(newLocalDateTime, _zone);
    }