UPSC Prelims 2025Question 77Geography

Consider the following statements:
I. Anadyr in Siberia and Nome in Alaska are a few kilometers from each other, but when people are waking up and getting set for breakfast in these cities, it would be different days.
II. When it is Monday in Anadyr, it is Tuesday in Nome.
Which of the statements given above is/are correct?

Options

Correct answer: a

Decision rule

Crossing the Date Line westward adds a day, eastward subtracts one: the Asian side is ahead, its neighbour across the strait earlier.

(a) I only

Let us evaluate both statements in the context of geography and the International Date Line (IDL).

Correct
Anadyr is in Russia’s Chukotka region, just across the Bering Strait from Nome, Alaska (USA).
While geographically close (separated by the Bering Strait, ~80 km at the narrowest point), they are on opposite sides of the International Date Line (IDL).
Hence, despite being close in space, they are a full day apart in time zones.
So, while it's morning in both, one city is a calendar day ahead of the other.

Incorrect
The actual time difference is Anadyr (UTC+12) and Nome (UTC−9).
That’s a 21-hour difference, not a full calendar day in the reverse direction.
So, when it is Monday in Anadyr, it is still Sunday in Nome, not Tuesday.
This confuses the direction of time change across the International Date Line.

City	Country	Time Zone	UTC Offset	Relative Day (from UTC)
Anadyr	Russia	Anadyr Time	UTC+12	Ahead of UTC by 12 hrs
Nome	USA	Alaska Standard	UTC−9	Behind UTC by 9 hrs
Time Difference	—	—	—	21 hours (Anadyr ahead)
Calendar Day	—	—	—	Often different days

Concept	Explanation
International Date Line	An imaginary line around 180° longitude where the calendar date changes.
Time Zones	Geographically defined areas with the same standard time offset from UTC.
Bering Strait	Water body separating Russia (Anadyr) and Alaska (Nome); near the IDL.
Anadyr Time (ANAT)	Time zone used in easternmost Russia; among the earliest to greet a new day.
Alaska Time Zone (AKST)	Time zone for western Alaska, behind UTC by 9 hours.

Concept / Term	Explanation / Relevance
International Date Line (IDL)	An imaginary line around 180° longitude (with deviations) where the calendar date changes by one day when crossed.
Time Zones	Earth is divided into 24 time zones, each roughly 15° of longitude apart, with UTC as the reference.
UTC (Coordinated Universal Time)	The global standard for time reference; all time zones are measured as offsets from UTC.
Anadyr (Russia)	Located in the Chukotka region, near the Bering Strait; follows UTC+12; one of the first places to see a new day.
Nome (Alaska, USA)	Located across the Bering Strait from Anadyr; follows UTC−9; among the last places to see the day end.
Time Difference (Anadyr vs. Nome)	21 hours (Anadyr is ahead), despite being only ~80 km apart geographically.
Calendar Day Shift	Due to IDL, places like Anadyr and Nome are often on different days, even during the same local hour.
Bering Strait	Narrow sea passage between eastern Russia and western Alaska; separates Asia from North America and is crossed by the IDL.
Date Line Anomalies	The IDL zigzags around territories like Kiribati, Fiji, Russia to ensure administrative uniformity in date/time.
Effect of Crossing IDL	Crossing from west to east = go back one day; crossing east to west = move ahead one day.