#include<iostream>
using namespace std;
int main()
{
    std::time_t t = std::time(0);  // t is an integer type
    float timestamp = t;
    cout << "Stempel: " << timestamp;
    cout << "\nStempel: " << t;
    return 0;
}

Stempel: 1.63171e+09
Stempel: 1631706077