import 'package:intl/intl.dart'; extension DateTimeNullableX on DateTime? { String yyyyMMDDFormat({String gap = "-"}) { if (this == null) return ""; return DateFormat("yyyy${gap}MM${gap}dd HH:mm:ss").format(this!); } String ymdSMFormat({String gap = "-"}) { if (this == null) return ""; return DateFormat("yyyy${gap}MM${gap}dd HH:mm").format(this!); } }