날짜와 Duration

DateTime  now = DateTime.now();

Duration duration = const Duration(seconds: 600); //600

설명	구현	샘플
현재날짜	now	2023-11-06 12:03:40.556
현재연도, 월 등	now.year now.month now.day now.hour	2023 11 06 11
특정 날짜 지정	DateTime sday = DateTime(2023, 11, 06);	2023-11-06 00:00:00.000
Duration 환산	duration.inDays duration.inHours duration.inMinutes	0  0 10
두개의 날짜 비교	final diff = now.difference(sday);  diff diff.inDays diff.inHours diff.inMinutes	12:03:40.556000 0 12 723
날짜 +	now.add(   Duration(hours: 10), );	2023-11-06 22:03:40.556
날짜 -	now.subtract(   Duration(hours: 10), );	2023-11-06 02:03:40.556