Current Time in a City

World clock - an interactive tool for checking the time on the globe

In the era of globalization, remote work for companies around the world, frequent travel and international social relationships, precise orientation in time zones is a necessity. Checking what time it is now in New York, London, Tokyo or Sydney protects us from making a business call in the middle of the night or being late for an important webinar. Our interactive world clock (World Clock) is an advanced tool that allows you to instantly check the current local time in thousands of cities around the world, automatically taking into account seasonal time changes (DST) and time differences from Poland.

Below you will find the history of standardization of time around the world, an explanation of concepts such as GMT and UTC, half zones and the principles of operation of date lines.

How did time zones come about? A short history of time unification

Before time zones were introduced, each city in the world used its own local solar time, determined based on the moment the sun crossed the meridian. This meant that when traveling several dozen kilometers by train, you had to set your watch by a few minutes. The development of railways and the telegraph in the 19th century forced changes. The creator of the concept of time zones was Canadian engineer Sir Sandford Fleming, who in 1876 proposed dividing the globe (360 degrees) into 24 time zones, each with a width of 15 degrees of longitude (360 / 24 = 15). In 1884, during the International Meridian Conference in Washington, the meridian running through the Greenwich Observatory in London was officially adopted as the Prime Meridian (GMT -Greenwich Mean Time), which is the basis for determining zones in the world.

Structure of time zones - differences between UTC, GMT and half zones

The modern time measurement system is based on two main standards:

• GMT (Greenwich Mean Time):Greenwich mean time, based on the rotation of the Earth around its axis. Traditionally used in navigation and meteorology.
• UTC (Coordinated Universal Time):Coordinated universal time, based on ultra-precise measurements of atomic clocks, regularly corrected for leap seconds. It is the official database for modern time zones.

Unusual half-hour and quarter-hour zones

It is worth knowing that not all time zones in the world differ by full hours. Some countries have made an autonomous decision to introduce shifts of half an hour or even 45 minutes in order to more closely match the official time to the actual position of the sun over their territory. The most important and largest country in terms of population using half time is India, where the UTC+5:30 zone (Indian Standard Time) applies. In turn, Nepal, wanting to distinguish itself from India and adjust the time to the summit of Mount Everest, uses a shift of 45 minutes, using the UTC+5:45 zone. Other half-shift countries include: Iran (UTC+3:30), Afghanistan (UTC+4:30), Sri Lanka (UTC+5:30), Myanmar (UTC+6:30) and the Australian Northern Territory (UTC+9:30).

International Date Line

A direct consequence of the introduction of time zones is the need for a line on which the day in the calendar changes. The International Date Line runs along the 180th geographic meridian in the Pacific Ocean, but bypasses inhabited islands so as not to disturb the lives of their inhabitants. Crossing this line westwards (from America to Asia) results in the need to add one day to the calendar (e.g. we immediately jump from Monday to Tuesday). The opposite direction (from Asia to America) means you have to go back one day, which allows you to metaphorically "go back in time".

Table of time zones of selected world capitals and their relations to Poland

The table below shows time shifts in relation to UTC time and the current hourly difference in relation to Poland (at standard winter time in Warsaw):

Frequently asked questions (FAQ)