// set by construct argument or as below
timer.Recursive(true);

// Stopped by destruction or as below
timer.Stop();

boost::asio::io_context ioc;
boost::asio::io_context::strand strand{ioc};
DurationTimer timer{strand, std::chrono::second{1}};

template <class IntervalType = std::chrono::hours,
          class IOExecutor   = boost::asio::io_context,
          class Timer        = boost::asio::system_timer,
          class TimePoint    = GetTimeType<Timer>>
class PointTimer

auto second_from_now =
   std::chrono::system_clock::now() + std::chrono::seconds{1};
boost::asio::io_context ioc;

PointTimer timer{ioc, second_from_now};
timer.Start([]() { std::cout << "timer expired." << std::endl; }); 

ioc.run();

template <class IntervalType = std::chrono::milliseconds,
          class IOExecutor   = boost::asio::io_context,
          class Timer        = boost::asio::steady_timer>
class DurationTimer

auto start_time = std::chrono::steady_clock::now();
boost::asio::io_context ioc;

DurationTimer timer{ioc, std::chrono::duration<double>{1}, false};
timer.Start([]() { std::cout << "timer expired." << std::endl; });

ioc.run();

using namespace boost::posix_time;
auto second_from_now = second_clock::universal_time() + seconds{1};
boost::asio::io_context ioc;

PointTimer<hours, boost::asio::io_context, boost::asio::deadline_timer> timer{
    ioc, second_from_now};
timer.Start([]() { std::cout << "timer expired." << std::endl; });
ioc.run();

auto start_time = std::chrono::steady_clock::now();
boost::asio::io_context ioc;
boost::asio::io_context::strand strand{ioc};

DurationTimer timer{strand, std::chrono::second{1}, false};
timer.Start([]() { std::cout << "timer expired." << std::endl; });

ioc.run();