I need to execute a function once, at certain times of the day, like this pseudo code:

while(true)
{
    now = Now();
    
    if(now == 16:00 or now == 22:00)
    {
        call_function();
    }
}

I do use chrono Timepoints quote often, but always for relative arithmetic comparisons like this:

if(now >= prev_ts + std::chrono::minutes(30))
{
    // do something
    prev_ts = now;

and this won’t work because the first invoccation will be immediately, whereas I need it to happen at the next 16:00.

What is the cleanest way to achieve this using C++23?

What’s confusing me is I don’t care about dates, nor do I care about offsets. I want something which is just a time object, not a datetime.