Europe
In Europe, the rule was signed by a group of countries, and it is known as the Schengen Treaty. These countries include Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovak Republic, Slovenia, Spain, Sweden, and Switzerland.The Schengen Treaty refers to a 3+3 rule where the passport must have a three-month validity and maximum stay time is three months. So, together the passport must have a minimum of six months validity to enter and stay in the country