How to get the amount of days between two datetime objects in flutter-CodePudding

I want to find the difference in days between two different datetimes in flutter.

in other words, i want to subtract two dates and get the difference between them
I found a way to do this in c# here. But unfortunately this doesn't apply for flutter.

Any help is appreciated

CodePudding user response：

You can use difference method of DateTime class to get the duration between two dates in dart.

 DateTime date1 = new DateTime.now();
 DateTime date2 = DateTime(2021, 1, 1);
 print(date1.difference(date2).inDays); // Prints 356 days

CodePudding user response：

// get current date & time

  DateTime startDate = DateTime.now();
        String currentTime = formatISOTime(startDate);

//convert date to String

String formatISOTime(DateTime date) {
    var duration = date.timeZoneOffset;
    if (duration.isNegative)
      return (date.toIso8601String()  
          "-${duration.inHours.toString().padLeft(2, '0')}:${(duration.inMinutes - (duration.inHours * 60)).toString().padLeft(2, '0')}");
    else
      return (date.toIso8601String()  
          " ${duration.inHours.toString().padLeft(2, '0')}:${(duration.inMinutes - (duration.inHours * 60)).toString().padLeft(2, '0')}");
  }

//calculate time difference

String? timediffference = calculateTimeDifferenceBetween(
                              givenDate ?? '',
                              currentTime) ??
                          '',

 static String? calculateTimeDifferenceBetween(
      String? givenDate, String? currentTime) {
    if (givenDate == null ||
        givenDate.isEmpty ||
        currentTime == null ||
        currentTime.isEmpty) {
      return "";
    } else {
      String gDate = givenDate.replaceAll('T', ' ');

      String curTime = currentTime.replaceAll('T', ' ');

      DateTime startParseDate =
          new DateFormat("yyyy-MM-dd HH:mm:ss").parse(curTime);
      DateTime endParseDate =
          new DateFormat("yyyy-MM-dd HH:mm:ss").parse(gDate);

      Duration diff = startParseDate.difference(endParseDate);

      if (diff.inDays >= 1) {
        return '${diff.inDays} day ago';
      } else if (diff.inDays >= 30) {
        return '${diff.inDays % 30} months ago';
      } else if (diff.inDays >= 365) {
        return '${diff.inDays % 365} years ago';
      } else if (diff.inHours >= 1) {
        return '${diff.inHours} hours ago';
      } else if (diff.inHours < 1) {
        if (diff.inMinutes >= 1) {
          return '${diff.inMinutes} minutes ago';
        } else if (diff.inMinutes < 1) {
          return  'just now ';
        } else {
          return 'just now ';
        }
      } else {
        return 'just now ';
      }
    }
  }