Time is a concept that varies across cultures and history. While we often think of it as universal, timekeeping has been shaped by politics, religion, and economics. Different societies have used various calendars, some based on the sun, others on the moon. Even today, while the Gregorian calendar is widely used, other calendars remain important for cultural and religious reasons. The Industrial Revolution shifted time perception from natural cues to rigid schedules, impacting how societies function. Time zones, too, are political creations, not purely scientific.