Dart for Flutter中的日期差异

Question

Playing in Flutter, using Dart - I am trying to establish the amount of seconds between two dates.

But for some reason the date1.difference(date2).inSeconds gives a result that does not make sense to me. Maybe it is late and I am too tired to miss something here:

Here is my code: (ie print statements of the dates and its supposed difference in seconds):

print(myDate);  // DateTime type
print(queryDate); // DateTime type
print(myDate.difference(queryDate).inSeconds);

And the print-results say:

2019-02-01 00:18:00.000Z     // myDate
2019-02-01 01:17:18.859431   // queryDate
41                           // supposedly difference in seconds...

But shouldn't it be much more than 41 seconds ????

Could the reason be the x.000Z vs. .859431 format differences ? And if yes, why ?

Why is the difference method ignoring minutes and hours ?

Answer 1

I found a solution:

Turns out, the queryDate was in another format (not sure what .859431 means - maybe somebody can explain ...?)

At least, when I do the following, it works:

DateTime queryDate2 = DateTime.utc(
                        queryDate.year,
                        queryDate.month,
                        queryDate.day,
                        queryDate.hour,
                        queryDate.minute,
                        queryDate.second);

Then my print-statements are:

print(myDate);      // DateTime type in UTC
print(queryDate);   // DateTime type in .859431 format (??)
print(queryDate2);  // DateTime type in UTC
print(myDate.difference(queryDate2).inHours);
print(myDate.difference(queryDate2).inMinutes);
print(myDate.difference(queryDate2).inSeconds);

And the print-results say:

2019-02-01 00:18:00.000Z    // myDate
2019-02-01 02:01:21.081575  // queryDate
2019-02-01 02:01:21.000Z    // queryDate2
-1                          // difference in hours   (now correct !)
-103                        // difference in minutes (now correct !)
-6201                       // difference in seconds (now correct !)

Yes, more like it :) (..now hours, minutes and seconds are correct).

Maybe there is another way of changing a date to UTC ? Any idea appreciated.

Answer 2

Try this package, Jiffy . Handle all of your questions. It follows the momentjs library and respect the number of days in a month and leap years to try to get the at least best result