How to convert seconds (double) to QDateTime in Qt?

Question

I have a number of seconds stored in a double format (but they are integer values if that's to be concerned). I would like to convert them to a hh:mm:ss format string. How to do that?

For example double secs = 120; would be 00:02:00.

What does the `secs` variable really contain? Are these seconds since beginning of the day or since 1.1.1970 which is Unix time (https://en.wikipedia.org/wiki/Unix_time)? — tomvodi, Jun 15 '15 at 08:09
if it cant be a real number, why not `int` or even `long long`? — Zaiborg, Jun 15 '15 at 08:57
I am just storing it as double because of other functionalities. I Convert it to int. — Łukasz Przeniosło, Jun 15 '15 at 08:59

Bowdzone · Accepted Answer · 2015-06-15T08:30:05.670

9

You can create a QTime object by using its default constructor and then add your seconds to it:

double secs = 120;

QTime a(0,0,0);
a = a.addSecs(int(secs));

edited Jun 15 '15 at 08:30

answered Jun 15 '15 at 07:58

Bowdzone

3,827
11
39
52

Same in here, I get empty string when converting time. – Łukasz Przeniosło Jun 15 '15 at 08:09
@ŁukaszPrzeniosło You're right, I fixed it. The `QTime` is invalid when not initialized with `0,0,0` or any other actual time values. Answer edited – Bowdzone Jun 15 '15 at 08:17
1

You might write `a = a.addSecs(int(secs));` too and do not involve second `QTime` object. – vahancho Jun 15 '15 at 08:28

score 1 · Answer 2 · answered Jun 15 '15 at 08:00

1

Why can't you convert seconds into hours, mins and seconds?

double secsDouble = 3666.0; // 1 hour, 1 min, 6 seconds.
int secs = (int)secsDouble;

int h = secs / 3600;
int m = ( secs % 3600 ) / 60;
int s = ( secs % 3600 ) % 60;

QTime t(h, m, s);
qDebug() << time.toString("hh:mm:ss");

answered Jun 15 '15 at 08:00

vahancho

20,808
3
47
55

1

I could do this but I thought there is an automatic method. – Łukasz Przeniosło Jun 15 '15 at 08:09

synacker · Answer 3 · 2015-06-15T08:10:52.867

0

QTime time;
time = time.addSecs((int)secs);
qDebug() << time.toString("hh:mm:ss");

edited Jun 15 '15 at 08:10

answered Jun 15 '15 at 07:58

synacker

1,722
13
32

1

For some reason this procedure doesnt work. When I convert the time to string I get an empty string. – Łukasz Przeniosło Jun 15 '15 at 08:09
Same effect, empty string. – Łukasz Przeniosło Jun 15 '15 at 08:14
@ŁukaszPrzeniosło Don't know why. I copy paste this code, and he work fine. – synacker Jun 15 '15 at 08:27
I had to declare time with default values like @Bowdzone explained – Łukasz Przeniosło Jun 15 '15 at 08:28
@ŁukaszPrzeniosło very strangely, by default, from http://doc.qt.io/qt-5/qtime.html , default values are the same. – synacker Jun 15 '15 at 08:34

How to convert seconds (double) to QDateTime in Qt?

3 Answers3