Error with QDateEdit and current time

[Carque]

I have the following example code in c++

QDate fecha = QDate::currentDate();
QDateEdit *entrada = new QDateEdit(fecha);
Registro::Aviso(fecha.toString().toStdString());
Registro::Aviso(entrada->date().toString().toStdString());

It worked perfectly until September 11, 2022 that shows the date of September 14, 1752, today it works fine again, I am in the chile/continental time zone, on September 10 the time was changed from 11:59 p.m. 01:00

Terminal output (September 10, 2022)

[2022-09-10 18:14:14][AVISO] sáb sep. 10 2022
[2022-09-10 18:14:14][AVISO] sáb sep. 10 2022

Terminal output (September 11, 2022)

[2022-09-11 18:00:10][AVISO] dom sep. 11 2022
[2022-09-11 18:00:10][AVISO] jue sep. 14 1752

Terminal output (September 12, 2022)

[2022-09-12 18:14:45][AVISO] lun sep. 12 2022
[2022-09-12 18:14:45][AVISO] lun sep. 12 2022

[JonB]

@Carque said in Error with QDateEdit and current time:

I am in the chile/continental time zone, on September 10 the time was changed from 11:59 p.m. 01:00

That means that on Sep 10/11 a local time between 00:00 and 01:00 "does not exist", there was no 00:00 or 00:30, agreed? I imagine in some shape or form you passed such an "illegal" datetime to a Qt datetime routine, and got back "illegal" from it. (See bool QDateTime::isValid() const and the notes there.) That probably returned something like a datetime of 0, and I would imagine that maps to the year 1752, hence your output.

I am guessing that QDate treats the time element as 00:00. You will have to do something about this to get a correct conversion.

[Carque]

I found an approximation of solution, don't pass the date through the constructor and use the setDate method instead.
because? I dont know

QDate fecha = QDate::currentDate();
QDateEdit *entrada = new QDateEdit();
entrada->setDate(fecha);

The other problem with this was

QDate local_date = QDate::fromString("2022-09-11", "yyyy-MM-dd");

this returns year 0

instead I had to use

QDate local_date = QDate::fromString("2022-09-11T00:00:00", Qt::ISODate);

because as JonB says it is not a valid time, but I am not interested in the time, I am only interested in the date, I am going to have to read the local date and save it as a utc date?.

[JonB]

@Carque said in Error with QDateEdit and current time:

I am in the chile/continental time zone, on September 10 the time was changed from 11:59 p.m. 01:00

That means that on Sep 10/11 a local time between 00:00 and 01:00 "does not exist", there was no 00:00 or 00:30, agreed? I imagine in some shape or form you passed such an "illegal" datetime to a Qt datetime routine, and got back "illegal" from it. (See bool QDateTime::isValid() const and the notes there.) That probably returned something like a datetime of 0, and I would imagine that maps to the year 1752, hence your output.

I am guessing that QDate treats the time element as 00:00. You will have to do something about this to get a correct conversion.

[Carque]

@JonB How can I save a local date as utc without saving the time? I think I can't because it would end up confusing days. but the invoice do not have hour and I can not invent one

[JonB]

@Carque
Sorry, I don't know what you mean. You can't have a "local" date in, or to convert to, UTC without involving the time, because UTC/timezones involve times.

[Carque]

@JonB I know but QDateEdit insists on passing me a date from utc to local adding 00:00:00 as the time and it changes me from 2022-09-11 to 2022-09-10, I think the easiest solution is to tell it that this all in utc

m_fecha = new QDateEdit(this);
m_fecha->setTimeSpec(Qt::UTC);
m_fecha->setDate(QDate::currentDate());

[JonB]

@Carque said in Error with QDateEdit and current time:

I think the easiest solution is to tell it that this all in utc

Indeed so! If you can afford to always work in UTC --- and if you're only interested in dates without times that seems reasonable anyway --- you avoid those pesky timezone conversions which can mess up the date.