DateTime returns wrong value when adding 7 days to the "2021-10-25" date

[IFL-byte]

This code prints a wrong value 2021-10-31 instead of the correct value that would be 2021-11-1.

void main() {
DateTime date = DateTime.parse("2021-10-25");
DateTime date2 = date.add(Duration(days: 7));
print(date2);
}

I tried with other similar dates as "2021-01-25" and it works perfectly but not for the one I mentioned above.

[julemand101]

See: #37449

[lrhn]

Yes, this is working as intended. Durations are millisecond counts, they do not understand the concept of days, a "day" is just 86400000 milliseconds. Local time-zone DateTime objects have hours, minutes, etc. too, even if they are zero.
And they're subject to local daylight saving changes to time zones.

Use UTC-dates when you want to represent calendar days.