How to validate whether my data is x seconds old using chrono package?

I am trying to see whether my data is 120 second old or not by looking at the timestamp of the data so I have below small code in my project which is using std::chrono package:

uint64_t now = duration_cast<milliseconds>(steady_clock::now().time_since_epoch()).count();
bool is_old = (120 * 1000 < (now - data_holder->getTimestamp()));

// some logging to print out above values
LOG4CXX_WARN(logger, "data logging, now: " << now << ", data holder timestamp: " << data_holder->getTimestamp() << ", is_old: " << is_old << ", difference: " << (now -         data_holder->getTimestamp()));

In the above code data_holder->getTimestamp() is uint64_t which returns timestamp in milliseconds.

Now when I print out now variable value, I am seeing this 433425679 and when I print out data_holder->getTimestamp() value which is 1437943796841 and the difference of now and data holder timestamp is coming as 18446742636199180454 as shown below in the logs:

2015-07-26 13:49:56,850 WARN 0x7fd050bc9700 simple_process - data logging, now: 433425679 , data holder timestamp: 1437943796841 , is_old: 1 , difference: 18446742636199180454

Now if I convert data holder timestamp 1437943796841 using epoch converter, I see this:

Your time zone: 7/26/2015, 1:49:56 PM

which is exactly same as the timestamp shown in the logs 2015-07-26 13:49:56,850 WARN so that means my data doesn't look to be 120 second old data. If yes, then why I am seeing is_old value as 1?

Now if I run this simple main program, I see is_old is returning 0 instead of 1:

#include <iostream>

int main ()
{

bool is_old = (120 * 1000 < (433425679 - 1437943796841));
std::cout<<"is_old: " << is_old << std::endl;
}

What is going on? Why it is returning 0 when I run from main method as compared to 1 when I log it from my project. Does that mean the way I am running my main code is different as compared to way my library was build using cmake command? I am building my project executable using cmake command which is generating a tar file and then I am running it by untarring the tar file. I am running on Ubuntu 14.04 box.

Earlier, I was thinking I need to use system_clock instead of steady_clock but after I run it from main method, it looks like something else is going on.