std::chrono::time_point::max

#include <chrono>
#include <vector>
#include <iostream>
 
int main() 
{
    std::chrono::time_point<std::chrono::system_clock> now =
        std::chrono::system_clock::now();
    std::vector<std::chrono::time_point<std::chrono::system_clock>> times {
        now - std::chrono::hours(24),
        now - std::chrono::hours(48),
        now + std::chrono::hours(24),
    };  
 
    std::chrono::time_point<std::chrono::system_clock> earliest =
        std::chrono::time_point<std::chrono::system_clock>::max();
 
    std::cout << "all times:\n";
    for (const auto &time : times) {
        std::time_t t = std::chrono::system_clock::to_time_t(time);
        std::cout << std::ctime(&t);
 
        if (time < earliest) earliest = time;
    }
 
    std::time_t t = std::chrono::system_clock::to_time_t(earliest);
    std::cout << "earliest:\n" << std::ctime(&t);
}