Countries around the world differ in how they write today’s date. Month first? Day first? Periods vs. dashes vs. slashes—everyone does it a little differently.

From 12-hour clocks to 24-hour military time, different regions use various clock formats. Certain countries even use one format orally and the other in written communication.

Not all countries observe Daylight Saving Time, and those that do might change their clocks at different times of the year—or not at all.

The starting day of the week varies globally, with some regions beginning on Sunday and others on Monday or Saturday.

The concept of weekdays and weekends isn't universal. While many countries follow a Monday-to-Friday workweek, others observe different days off based on cultural or religious traditions.