These are really good libraries that got my dates and times flowing client-server full circle, with all the UI and math tools I needed.
KISS!
// Date sanitation: limit ancient and future days and ensure start isn't beyond end
date today = second_clock::local_time().date();
date s = startdate;
date e = enddate;
if (e > today)
e = today;
if (e - s > date_duration(cn_max_days_to_look_back))
s = e - date_duration(cn_max_days_to_look_back);
if (s > e)
s = e;
