Learn how weekday rules determine moveable civil holidays like US Thanksgiving and Mother’s Day. Get simple algorithms, recurrence patterns, and planning tips so you can schedule, budget, and communicate with confidence.
Explore how international days, weeks, and years come to life—from UN resolutions to national proclamations. Learn the criteria, campaigns, and politics that determine which causes earn official observance status.
Explore how Earth’s tilt and orbit create solstices and equinoxes, and why these precise astronomical moments anchor many secular seasonal observances around the world. Includes clear timing differences for the Northern and Southern Hemispheres, plus practical tips for celebrating the seasons.
Discover how different cultures celebrate 'name days,' special calendar dates connected to given names through religious or cultural traditions. Learn where they come from, how various countries observe them, and how to find your own name day.
Discover how the International Date Line and global time zones can shift holidays, birthdays, and digital ‘on this day’ moments. Learn how travelers, content editors, and social media managers can keep important dates consistent around the world.
Discover the fascinating customs, legal quirks, and historical challenges surrounding February 29. Learn how leap-year birthdays, anniversaries, and events are handled across cultures and institutions.
Discover why the birthday paradox defies common sense and why shared birthdays happen more often than expected, with clear math, practical examples, and actual real-world datasets.
As the crescent moon is sighted, marking the end of Ramadan, Muslims all over the world prepare to celebrate Eid al-Fitr. The festival typically lasts for three days and is marked by a variety of traditions and customs that vary from country to country.
The gregorian calendar has been a staple of timekeeping in the western world for a long time, even before its namesake Pope Gregory XIII. That begs the question, where did we get our months' names?
Since the dawn of time, man needed tools to measure time and help him in secular and religious matters. Questions like: When do we plant? When do we go to war? When should the tax collector show up? The dates of religious festivals and popular events all require a well-calibrated system and knowledge.
Horror movies, huge pumpkins, candy, and costume parties. These things remind us of only one thing… It's Halloween again, but have you ever wondered about its origin? Why is it celebrated? How did this tradition begin?
Islam is a monotheistic Abrahamic religion originated in the Arabian Peninsula 1400 years ago, and spread rapidly to form a majority of the population in the Middle East and many Asian and African countries. Islam now is followed by more than a billion people, making it the second largest religion in the world.
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