  :::::I agree with option 1. I would extend option 2 to include sub-Saharan Africa, Australia/Oceana, and Asia except south Asia from Burma west, areas where the Bhuddist, Hindu, and Islamic calendars are used more in daily life. I include within the umbrella of the Gregorian calendar the calendars of China, Korea, and Japan which number the months instead of naming them and those of Thailand and Japan which don't use the Anno Domini/Common era to number the years. Whether we want to include such a detailed list or any list is open for discussion. —   