Flutter elapsed time

Question

How do you show how much time has elapsed since from example 16 May 2023? In years, months, weeks, days, hours, minutes and seconds? The idea is that after 4 weeks it would show 1 month and 0 weeks. Thanks

Answer 1

Here's a simple function to find the days in between dates:

int daysBetween(DateTime from, DateTime to) {
   from = DateTime(from.year, from.month, from.day);
   to = DateTime(to.year, to.month, to.day);
   return (to.difference(from).inHours / 24).round();
}

final date1 = DateTime(2023, 5, 16);
final date2 = DateTime.now();
final difference = daysBetween(date1, date2);

Then you want to convert the days to it's most optimal units. This can be done by checking if it's over a threshold (for example 7 days) then dividing it by the threshold to convert days to that unit.

For example, if you want to convert days into weeks:

if (numberOfDays >= 7) {
  numberOfWeeks = numberOfDays / 7;
}

You can then chain this with months, years, etc. :

if (numberOfDays >= 365.25) {
  numberOfYears = (numberOfDays / 365.25).round();
  numberOfDays = numberOfDays - (numberOfYears * 365.25);
}

if (numberOfDays >= 30.437) {
  numberOfMonths = (numberOfDays / 30.437).round();
  numberOfDays = numberOfDays - (numberOfMonths * 30.437);
}

if (numberOfDays >= 7) {
  numberOfWeeks = (numberOfDays / 7).round();
  numberOfDays = numberOfDays - (numberOfWeeks * 7);
}

final differenceWithUnits = DateTime(numberOfYears, numberOfMonths, (numberOfWeeks * 7) + numberOfDays)

365.25 is the average number of days in a year, 30.437 is the average number of days in a month, and 7 is obviously the average number of days in a week.

In the differenceWithUnits, it only takes years, months, and days, so I converted weeks & days into just days.

Hope this helps!

I got the first part from: https://stackoverflow.com/a/52713358/16098405