Save the differences between two dates in list flutter - flutter

I want to store the dates between two dates in list for example if the
start date = 3/4/2021 and the end date = 7/4/2021
then the list items are [3/4/2021,4/4/2021,5/4/2021,6/4/2021,7/4/2021]
DateTime medStartDate =
doc[index]['medicationStartDate'].toDate();
DateTime medEndDate = doc[index]['medicationEndDate'].toDate();
final difference = medEndDate.difference(medStartDate).inDays;
but how to save the dates ?

You can iterate over a range like this:
void main() {
final startDate = DateTime.now();
final endDate = startDate.add(Duration(days: 5));
final interval = calculateInterval(startDate, endDate);
print(interval);
}
List<DateTime> calculateInterval(DateTime startDate, DateTime endDate) {
List<DateTime> days = [];
for (int i = 0; i <= endDate.difference(startDate).inDays; i++) {
days.add(startDate.add(Duration(days: i)));
}
return days;
}
And the result:
[2021-04-07 16:27:15.480, 2021-04-08 16:27:15.480, 2021-04-09 16:27:15.480, 2021-04-10 16:27:15.480, 2021-04-11 16:27:15.480, 2021-04-12 16:27:15.480]

Related

How to get the next near future value to the current time in a list in Flutter?

I have a store schedule that comes from the server. And I get the current time. I need to find the near future start_time to my current time in the list I am getting. For example, if the current time is 3:00 pm, I need to get the closest start_time, which is 5:00 pm. Tell me how to do it?
here I am accessing the key 'mon'
String dateFormat = DateFormat('EEE').format(timeNow).toLowerCase();
shopSchedule.templateFull![dateFormat]
You can do this to get closest time after now from your mon list:
String? selectedTime;
for (var element in mon) {
if (selectedTime == null) {
var now = DateTime.now();
DateTime tempDate = DateFormat("yyyy-MM-dd hh:mm").parse(
"${now.year}-${now.month}-${now.day} ${element["start_time"] as String}");
if (tempDate.isAfter(now)) {
selectedTime = element["start_time"];
}
} else {
var now = DateTime.now();
DateTime selectedDate = DateFormat("yyyy-MM-dd hh:mm")
.parse("${now.year}-${now.month}-${now.day} $selectedTime");
DateTime tempDate = DateFormat("yyyy-MM-dd hh:mm").parse(
"${now.year}-${now.month}-${now.day} ${element["start_time"] as String}");
if (tempDate.isBefore(selectedDate) && tempDate.isAfter(now)) {
selectedTime = element["start_time"];
}
}
}

how to get difference(remaining time ) between '22:00:00' & '00:22:00' in flutter [duplicate]

I'm working on a flutter app as a project and I'm stuck with how to get the difference between two times. The first one I'm getting is from firebase as a String, which I then format to a DateTime using this:DateTime.parse(snapshot.documents[i].data['from']) and it gives me 14:00 for example. Then, the second is DateTime.now().
I tried all methods difference, subtract, but nothing works!
Please help me to get the exact duration between those 2 times.
I need this for a Count Down Timer.
This is an overview of my code:
.......
class _ActualPositionState extends State<ActualPosition>
with TickerProviderStateMixin {
AnimationController controller;
bool hide = true;
var doc;
String get timerString {
Duration duration = controller.duration * controller.value;
return '${duration.inHours}:${duration.inMinutes % 60}:${(duration.inSeconds % 60).toString().padLeft(2, '0')}';
}
#override
void initState() {
super.initState();
var d = Firestore.instance
.collection('users')
.document(widget.uid);
d.get().then((d) {
if (d.data['parking']) {
setState(() {
hide = false;
});
Firestore.instance
.collection('historyParks')
.where('idUser', isEqualTo: widget.uid)
.getDocuments()
.then((QuerySnapshot snapshot) {
if (snapshot.documents.length == 1) {
for (var i = 0; i < snapshot.documents.length; i++) {
if (snapshot.documents[i].data['date'] ==
DateFormat('EEE d MMM').format(DateTime.now())) {
setState(() {
doc = snapshot.documents[i].data;
});
Duration t = DateTime.parse(snapshot.documents[i].data['until'])
.difference(DateTime.parse(
DateFormat("H:m:s").format(DateTime.now())));
print(t);
}
}
}
});
}
});
controller = AnimationController(
duration: Duration(hours: 1, seconds: 10),
vsync: this,
);
controller.reverse(from: controller.value == 0.0 ? 1.0 : controller.value);
}
double screenHeight;
#override
Widget build(BuildContext context) {
screenHeight = MediaQuery.of(context).size.height;
return Scaffold(
.............
you can find the difference between to times by using:
DateTime.now().difference(your_start_time_here);
something like this:
var startTime = DateTime(2020, 02, 20, 10, 30); // TODO: change this to your DateTime from firebase
var currentTime = DateTime.now();
var diff = currentTime.difference(startTime).inDays; // HINT: you can use .inDays, inHours, .inMinutes or .inSeconds according to your need.
example from DartPad:
void main() {
final startTime = DateTime(2020, 02, 20, 10, 30);
final currentTime = DateTime.now();
final diff_dy = currentTime.difference(startTime).inDays;
final diff_hr = currentTime.difference(startTime).inHours;
final diff_mn = currentTime.difference(startTime).inMinutes;
final diff_sc = currentTime.difference(startTime).inSeconds;
print(diff_dy);
print(diff_hr);
print(diff_mn);
print(diff_sc);
}
Output: 3,
77,
4639,
278381,
Hope this helped!!
You can use the DateTime class to find out the difference between two dates.
DateTime dateTimeCreatedAt = DateTime.parse('2019-9-11');
DateTime dateTimeNow = DateTime.now();
final differenceInDays = dateTimeNow.difference(dateTimeCreatedAt).inDays;
print('$differenceInDays');
final differenceInMonths = dateTimeNow.difference(dateTimeCreatedAt).inMonths;
print('$differenceInMonths');
Use this code:
var time1 = "14:00";
var time2 = "09:00";
Future<int> getDifference(String time1, String time2) async
{
DateFormat dateFormat = DateFormat("yyyy-MM-dd");
var _date = dateFormat.format(DateTime.now());
DateTime a = DateTime.parse('$_date $time1:00');
DateTime b = DateTime.parse('$_date $time2:00');
print('a $a');
print('b $a');
print("${b.difference(a).inHours}");
print("${b.difference(a).inMinutes}");
print("${b.difference(a).inSeconds}");
return b.difference(a).inHours;
}
To compute a difference between two times, you need two DateTime objects. If you have times without dates, you will need to pick a date. Note that this is important because the difference between two times can depend on the date if you're using a local timezone that observes Daylight Saving Time.
If your goal is to show how long it will be from now to the next specified time in the local timezone:
import 'package:intl/intl.dart';
/// Returns the [Duration] from the current time to the next occurrence of the
/// specified time.
///
/// Always returns a non-negative [Duration].
Duration timeToNext(int hour, int minute, int second) {
var now = DateTime.now();
var nextTime = DateTime(now.year, now.month, now.day, hour, minute, second);
// If the time precedes the current time, treat it as a time for tomorrow.
if (nextTime.isBefore(now)) {
// Note that this is not the same as `nextTime.add(Duration(days: 1))` across
// DST changes.
nextTime = DateTime(now.year, now.month, now.day + 1, hour, minute, second);
}
return nextTime.difference(now);
}
void main() {
var timeString = '14:00';
// Format for a 24-hour time. See the [DateFormat] documentation for other
// format specifiers.
var timeFormat = DateFormat('HH:mm');
// Parsing the time as a UTC time is important in case the specified time
// isn't valid for the local timezone on [DateFormat]'s default date.
var time = timeFormat.parse(timeString, true);
print(timeToNext(time.hour, time.minute, time.second));
}
You can use this approch
getTime(time) {
if (!DateTime.now().difference(time).isNegative) {
if (DateTime.now().difference(time).inMinutes < 1) {
return "a few seconds ago";
} else if (DateTime.now().difference(time).inMinutes < 60) {
return "${DateTime.now().difference(time).inMinutes} minutes ago";
} else if (DateTime.now().difference(time).inMinutes < 1440) {
return "${DateTime.now().difference(time).inHours} hours ago";
} else if (DateTime.now().difference(time).inMinutes > 1440) {
return "${DateTime.now().difference(time).inDays} days ago";
}
}
}
And You can call it getTime(time) Where time is DateTime Object.

Flutter: Check if date is between two dates

I need to check date is between two dates or not.
I tried to search it but didn't got fruitful results.
May be you have seen such scenarios. So, seeking your advise.
Here is my code.
var service_start_date = '2020-10-17';
var service_end_date = '2020-10-23';
var service_start_time = '10:00:00';
var service_end_time = '11:00:00';
DateTime currentDate = new DateTime.now();
DateTime times = DateTime.now();
#override
void initState() {
super.initState();
test();
}
test() {
String currenttime = DateFormat('HH:mm').format(times);
String currentdate = DateFormat('yyyy-mm-dd').format(currentDate);
print(currenttime);
print(currentdate);
}
So, basically i have start date and end date. I need to check current date is falling between these two dates or not.
You can check before/after using 'isBefore' and 'isAfter' in 'DateTime' class.
DateTime startDate = DateTime.parse(service_start_date);
DateTime endDate = DateTime.parse(service_end_date);
DateTime now = DateTime.now();
print('now: $now');
print('startDate: $startDate');
print('endDate: $endDate');
print(startDate.isBefore(now));
print(endDate.isAfter(now));
I've made a series of extensions
extension DateTimeExtension on DateTime? {
bool? isAfterOrEqualTo(DateTime dateTime) {
final date = this;
if (date != null) {
final isAtSameMomentAs = dateTime.isAtSameMomentAs(date);
return isAtSameMomentAs | date.isAfter(dateTime);
}
return null;
}
bool? isBeforeOrEqualTo(DateTime dateTime) {
final date = this;
if (date != null) {
final isAtSameMomentAs = dateTime.isAtSameMomentAs(date);
return isAtSameMomentAs | date.isBefore(dateTime);
}
return null;
}
bool? isBetween(
DateTime fromDateTime,
DateTime toDateTime,
) {
final date = this;
if (date != null) {
final isAfter = date.isAfterOrEqualTo(fromDateTime) ?? false;
final isBefore = date.isBeforeOrEqualTo(toDateTime) ?? false;
return isAfter && isBefore;
}
return null;
}
}
I'm hoping they're self explanatory but obviously you can call them like
DateTime.now().isBefore(yourDate)
DateTime.now().isAfter(yourDate)
DateTime.now().isBetween(fromDate, toDate)
Don't forget to check if the day is the same as the one of the two dates also
by adding an or to the condition ex:
if ( start is before now || (start.month==now.month && start.day==now.day ...etc)

How can I get the difference between 2 times?

I'm working on a flutter app as a project and I'm stuck with how to get the difference between two times. The first one I'm getting is from firebase as a String, which I then format to a DateTime using this:DateTime.parse(snapshot.documents[i].data['from']) and it gives me 14:00 for example. Then, the second is DateTime.now().
I tried all methods difference, subtract, but nothing works!
Please help me to get the exact duration between those 2 times.
I need this for a Count Down Timer.
This is an overview of my code:
.......
class _ActualPositionState extends State<ActualPosition>
with TickerProviderStateMixin {
AnimationController controller;
bool hide = true;
var doc;
String get timerString {
Duration duration = controller.duration * controller.value;
return '${duration.inHours}:${duration.inMinutes % 60}:${(duration.inSeconds % 60).toString().padLeft(2, '0')}';
}
#override
void initState() {
super.initState();
var d = Firestore.instance
.collection('users')
.document(widget.uid);
d.get().then((d) {
if (d.data['parking']) {
setState(() {
hide = false;
});
Firestore.instance
.collection('historyParks')
.where('idUser', isEqualTo: widget.uid)
.getDocuments()
.then((QuerySnapshot snapshot) {
if (snapshot.documents.length == 1) {
for (var i = 0; i < snapshot.documents.length; i++) {
if (snapshot.documents[i].data['date'] ==
DateFormat('EEE d MMM').format(DateTime.now())) {
setState(() {
doc = snapshot.documents[i].data;
});
Duration t = DateTime.parse(snapshot.documents[i].data['until'])
.difference(DateTime.parse(
DateFormat("H:m:s").format(DateTime.now())));
print(t);
}
}
}
});
}
});
controller = AnimationController(
duration: Duration(hours: 1, seconds: 10),
vsync: this,
);
controller.reverse(from: controller.value == 0.0 ? 1.0 : controller.value);
}
double screenHeight;
#override
Widget build(BuildContext context) {
screenHeight = MediaQuery.of(context).size.height;
return Scaffold(
.............
you can find the difference between to times by using:
DateTime.now().difference(your_start_time_here);
something like this:
var startTime = DateTime(2020, 02, 20, 10, 30); // TODO: change this to your DateTime from firebase
var currentTime = DateTime.now();
var diff = currentTime.difference(startTime).inDays; // HINT: you can use .inDays, inHours, .inMinutes or .inSeconds according to your need.
example from DartPad:
void main() {
final startTime = DateTime(2020, 02, 20, 10, 30);
final currentTime = DateTime.now();
final diff_dy = currentTime.difference(startTime).inDays;
final diff_hr = currentTime.difference(startTime).inHours;
final diff_mn = currentTime.difference(startTime).inMinutes;
final diff_sc = currentTime.difference(startTime).inSeconds;
print(diff_dy);
print(diff_hr);
print(diff_mn);
print(diff_sc);
}
Output: 3,
77,
4639,
278381,
Hope this helped!!
You can use the DateTime class to find out the difference between two dates.
DateTime dateTimeCreatedAt = DateTime.parse('2019-9-11');
DateTime dateTimeNow = DateTime.now();
final differenceInDays = dateTimeNow.difference(dateTimeCreatedAt).inDays;
print('$differenceInDays');
final differenceInMonths = dateTimeNow.difference(dateTimeCreatedAt).inMonths;
print('$differenceInMonths');
Use this code:
var time1 = "14:00";
var time2 = "09:00";
Future<int> getDifference(String time1, String time2) async
{
DateFormat dateFormat = DateFormat("yyyy-MM-dd");
var _date = dateFormat.format(DateTime.now());
DateTime a = DateTime.parse('$_date $time1:00');
DateTime b = DateTime.parse('$_date $time2:00');
print('a $a');
print('b $a');
print("${b.difference(a).inHours}");
print("${b.difference(a).inMinutes}");
print("${b.difference(a).inSeconds}");
return b.difference(a).inHours;
}
To compute a difference between two times, you need two DateTime objects. If you have times without dates, you will need to pick a date. Note that this is important because the difference between two times can depend on the date if you're using a local timezone that observes Daylight Saving Time.
If your goal is to show how long it will be from now to the next specified time in the local timezone:
import 'package:intl/intl.dart';
/// Returns the [Duration] from the current time to the next occurrence of the
/// specified time.
///
/// Always returns a non-negative [Duration].
Duration timeToNext(int hour, int minute, int second) {
var now = DateTime.now();
var nextTime = DateTime(now.year, now.month, now.day, hour, minute, second);
// If the time precedes the current time, treat it as a time for tomorrow.
if (nextTime.isBefore(now)) {
// Note that this is not the same as `nextTime.add(Duration(days: 1))` across
// DST changes.
nextTime = DateTime(now.year, now.month, now.day + 1, hour, minute, second);
}
return nextTime.difference(now);
}
void main() {
var timeString = '14:00';
// Format for a 24-hour time. See the [DateFormat] documentation for other
// format specifiers.
var timeFormat = DateFormat('HH:mm');
// Parsing the time as a UTC time is important in case the specified time
// isn't valid for the local timezone on [DateFormat]'s default date.
var time = timeFormat.parse(timeString, true);
print(timeToNext(time.hour, time.minute, time.second));
}
You can use this approch
getTime(time) {
if (!DateTime.now().difference(time).isNegative) {
if (DateTime.now().difference(time).inMinutes < 1) {
return "a few seconds ago";
} else if (DateTime.now().difference(time).inMinutes < 60) {
return "${DateTime.now().difference(time).inMinutes} minutes ago";
} else if (DateTime.now().difference(time).inMinutes < 1440) {
return "${DateTime.now().difference(time).inHours} hours ago";
} else if (DateTime.now().difference(time).inMinutes > 1440) {
return "${DateTime.now().difference(time).inDays} days ago";
}
}
}
And You can call it getTime(time) Where time is DateTime Object.

Dart: How to find number of days between two dates excluding Weekend or Predicate

I need to calculate number of days between two dates in Dart.
There is built in function for that.
leaveEndDate.difference(leaveStartDate).inDays
But I do not want weekends to be included.
Is there any way I can traverse between these 2 Dates or I can just exclude weekends.
I think you have no other choice than looping through all the days to check if this is a weekend day or not :
void main() {
DateTime date1 = DateTime(2019, 12, 01);
DateTime date2 = DateTime(2019, 12, 31);
print(getDifferenceWithoutWeekends(date1, date2));
}
int getDifferenceWithoutWeekends(DateTime startDate, DateTime endDate) {
int nbDays = 0;
DateTime currentDay = startDate;
while (currentDay.isBefore(endDate)) {
currentDay = currentDay.add(Duration(days: 1));
if (currentDay.weekday != DateTime.saturday && currentDay.weekday != DateTime.sunday) {
nbDays += 1;
}
}
return nbDays;
}
Result :
22
EDIT :
Another solution, not sure it is faster but can be useful if you need to identify the dates (you could return list<DateTime> instead of List<int> to see which day is a weekend day).
Here I build each days between the 2 dates and return 1 if this is not a weekend day, then sum the list :
void main() {
DateTime startDate = DateTime(2019, 12, 01);
DateTime endDate = DateTime(2019, 12, 31);
int nbDays = endDate.difference(startDate).inDays + 1;
List<int> days = List.generate(nbDays, (index) {
int weekDay = DateTime(startDate.year, startDate.month, startDate.day + (index)).weekday;
if (weekDay != DateTime.saturday && weekDay != DateTime.sunday) {
return 1;
}
return 0;
});
print(days.reduce((a, b) => a + b));
}
I have also prepared a function which will traverse to all dates between two dates in Dart and will calculate number of days inBetween.
int calculateDaysBetween(DateTime mStartDate, DateTime mEndDate) {
int leaveDays = mEndDate.difference(mStartDate).inDays + 1;
int leaveBalance = 0;
var mTempDateTime =
DateTime(mStartDate.year, mStartDate.month, mStartDate.day);
for (int i = 0; i < leaveDays; i++) {
mTempDateTime = DateTime(
mTempDateTime.year, mTempDateTime.month, mTempDateTime.day + 1);
if (mTempDateTime.weekday == DateTime.friday ||
mTempDateTime.weekday == DateTime.saturday) {
print('is weekend');
} else {
leaveBalance++;
}
print(mTempDateTime);
}
// Total number of days between two dates excluding weekends.
return leaveBalance;
}
Improve #Developine Answer and make it more reusable , I make 2 function.
1.Calculate Total Days Of Month
2.Calculate TotalWeekDayOfMonth
Get Total Days Of Month
int totalDaysOfMonth(int month, int year) {
final result = (month < 12) ? DateTime(year, month + 1, 0) : DateTime(year + 1, 1, 0);
return result.day;
}
Get Total WeekDay Of Month
int totalWeekDayOfMonth(int year, int month, {int day = 1}) {
int totalDayOfMonth = totalDaysOfMonth(year, month);
int result = 0;
DateTime tempDateTime = DateTime(year, month, day);
for (int i = day; i <= totalDayOfMonth; i++) {
tempDateTime = DateTime(tempDateTime.year, tempDateTime.month, i);
if (tempDateTime.weekday == DateTime.saturday || tempDateTime.weekday == DateTime.sunday) {
print('is weekend');
} else {
result++;
}
}
return result;
}
How To Use It
void main(){
final resultWithoutDay = totalWeekDayOfMonth(2019,12);
final resultWithDay = totalWeekDayOfMonth(2019,12,day: 16);
print("Without Day $resultWithoutDay"); // 22
print("With Day $resultWithDay"); // 12
}