Converting a UTC time to local time

McLion

Hi

From data received I get a UTC time for an event (it actually comes in as 4-bit coded BCD).
Is there some easy way to convert this to the local time?

Thanks

raven-worx

@McLion

int y = ...;
int mm = ...;
int d = ...;
int h = ...;
int m = ...;
int s = ...;
QDate date(y, mm, d);
QTime time(h, m, s);
QDateTime localTime = QDateTime(date, time, Qt::UTC).toLocalTime();

Now you just need to fill up the ints (e.g. by bit shifting and masking) of your received data.

McLion

Thanks - works a treat.
Here's my finished solution:

uchar h = BCDtoHex(inData->at(18));
uchar m = BCDtoHex(inData->at(19));
uchar s = BCDtoHex(inData->at(20));
QDate date;
if(h > 12)  date = QDate::fromJulianDay((inData->at(16) << 8) + inData->at(17) + 2400001);
else        date = QDate::fromJulianDay((inData->at(16) << 8) + inData->at(17) + 2400000);
QTime time(h, m, s, 0);
QDateTime localTime = QDateTime(date, time, Qt::UTC).toLocalTime();

The JulianDate thing needs some testing since my input data is in ModifiedJulianDate.
If it does not work like above I have an extensive calculation formula on hand. However, the above would be quicker.

McLion

I have a follow up question:
Is there an easy way to 'add' times - despite doing it manually and take care of the 'carry-over' at 60 and stuff?

uchar dh = BCDtoHex(inData->at(21));
uchar dm = BCDtoHex(inData->at(22));
uchar ds = BCDtoHex(inData->at(23));
QTime duration(dh, dm, ds, 0);

// now add this to time from above to get the endtime, i.e. something like:
QTime end = time + duration; 

QDateTime localEndTime = QDateTime(date, end, Qt::UTC).toLocalTime();

Thanks

raven-worx

@McLion
why don't you simply take a look at the QDateTime docs?! I am sure you will find the method on your own...

McLion

@raven-worx
Seems I was not looking at the right place or not well enough.

QTime zero(0, 0, 0, 0);
QDateTime EndTimeLocal = StartTimeLocal.addSecs(zero.secsTo(duration));

Thanks anyway :-)