Dual Threat: Why Keeping Two Calendars is a Terrible Idea | Jared Correia | Pulse | LinkedIn. Great article here by Jared Correia about calendaring. Perhaps a lawyer's biggest fear is missing a court date because of an error in a Calendar. Most of us are really careful about it. I agree that dual calendars are a bad idea. Transposition errors and conflicts can be a nightmare. However, in the computer age you should probably be keeping several calendars. I have one on my notebook computer, another on my smartphone, another on my tablet, another on my backup phone, and so on. The kicker is that any entry into any of them self populates to the others. Real time syncing is the best thing that ever happened to my calendaring, and we can thank cloud computing for it. So, keep one calendar; but, make sure it syncs in several places. That way you are always looking at the same data. If you are in a group practice, make sure that everybody is using the same live sync system. Now, get to Court. You're late.