Cross the International Date Line and find out exactly what date and time you arrive. Enter your departure date and time, select your origin time zone and destination time zone, and see the adjusted arrival date and time along with how many hours you've gained or lost.
Arrival Date & Time (Destination)
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Time Zone Difference
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Date Change
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Departure Time (UTC)
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Arrival Time (UTC)
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The International Date Line (IDL) is an imaginary line running roughly along the 180° meridian in the Pacific Ocean. It marks the boundary between two consecutive calendar dates — crossing it eastward moves you back one calendar day, while crossing it westward moves you forward one day.
Earth is divided into 24 time zones spanning 360°, meaning each hour corresponds to 15° of longitude. As you travel east you gain hours, and as you travel west you lose them. The IDL acts as the reset point — once you accumulate or lose a full 24 hours, the calendar date must change by one day to stay consistent worldwide.
It depends on your direction of travel. Traveling westward (e.g. from the Americas toward Asia/Australia) you cross into the next calendar day, gaining a day. Traveling eastward (e.g. from Asia/Australia toward the Americas) you go back one calendar day, effectively repeating a date.
UTC (Coordinated Universal Time) and GMT (Greenwich Mean Time) both reference the same zero-meridian point and are numerically identical for everyday purposes. The key distinction is that GMT is a time zone used by some countries, while UTC is the international time standard upon which all other time zones are based. Modern systems use UTC as the reference.
UTC-12 (International Date Line West) and UTC+12 (Auckland, Wellington, Fiji) sit on either side of the IDL. They share the same absolute moment in time but differ by exactly 24 hours in calendar date — making them the farthest apart in date while being geographically adjacent.
No — while it generally follows the 180° meridian, the IDL zigzags to avoid splitting countries and island groups across two different calendar dates. Notable deviations occur around Kiribati, Samoa, and the Aleutian Islands to keep politically or economically unified territories on the same calendar day.
Most time zones are offset from UTC by whole hours, but some regions use non-standard offsets. India and Sri Lanka use UTC+5:30, Nepal uses UTC+5:45, and parts of Australia use UTC+9:30. These offsets exist for geographic or political reasons and are fully valid — this calculator accounts for common half-hour offsets.
Yes — flights crossing the IDL westbound (e.g. Los Angeles to Sydney) can appear to arrive two calendar days after departure even if the flight is only 15 hours long. Conversely, eastbound flights (Sydney to Los Angeles) can land on the same calendar day or even the day before departure. This calculator helps you understand exactly what date and local time you'll arrive.