Openai/694d1b2b-4b80-800f-98dd-f97998a7c926

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gpt-5-2

User: At what time est will it be Christmas Day everywhere in the world

At what time est will it be Christmas Day everywhere in the world

Assistant: 7:00 AM Eastern Standard Time EST on December 25

7:00 AM Eastern Standard Time (EST) on December 25

Here’s why, step by step:

• The last places on Earth to reach Christmas Day are the uninhabited Baker Island and Howland Island, which sit in the UTC−12 time zone (the very end of the calendar).
• When it becomes 12:00 AM (midnight) on December 25 there, it is: - 12:00 PM (noon) UTC - 7:00 AM EST (UTC−5)

So at 7:00 AM EST on December 25, every single place on Earth is officially on Christmas Day.

Before that moment, at least one spot on the planet is still technically on December 24.

User: What about the last inhabited place

What about the last inhabited place

Assistant: The last inhabited place on Earth to reach Christmas Day is American Samoa, which is in UTC−11.

The last inhabited place on Earth to reach Christmas Day is American Samoa, which is in UTC−11.

So the answer is:

6:00 AM EST on December 25

Breakdown:

• American Samoa hits Christmas Day at: 12:00 AM local time (UTC−11)
• That moment corresponds to: - 11:00 AM UTC - 6:00 AM EST (UTC−5)

After 6:00 AM EST on December 25, every inhabited place on Earth is officially on Christmas Day.

The extra hour (until 7:00 AM EST) is only because of uninhabited time zones like Baker and Howland Islands (UTC−12).

User: And it won’t already be the 26th anywhere?

And it won’t already be the 26th anywhere?

Assistant: Correct — it will already be December 26 somewhere.

Correct — it will already be December 26 somewhere.

Here’s the clean, precise picture:

• The earliest places on Earth are in UTC+14 (the Line Islands of Kiribati, e.g., Kiritimati).
• The last inhabited place to reach Christmas Day is American Samoa (UTC−11).

When American Samoa hits 12:00 AM on Dec 25:

• That moment is 11:00 AM UTC
• 6:00 AM EST
• In UTC+14, it is already 1:00 AM on December 26

So the truth table is:

• ✅ By 6:00 AM EST on Dec 25, every inhabited place has experienced Christmas Day
• ❌ But Christmas Day is no longer happening everywhere at once
• 🎄 Some places are already into December 26

The only moment when:

• Some places are Dec 24
• Some are Dec 25
• Some are Dec 26

…is during that several-hour overlap on Christmas morning EST.

There is no single instant where everyone on Earth is simultaneously on December 25.

Time zones ruin the vibe. 🌍⏰

gpt-5-2-thinking

User: At what time is the highest percentage of the populated world on Christmas Day?

At what time is the highest percentage of the populated world on Christmas Day?

Assistant: The peak is essentially right before 12:00 UTC on Dec 25 — which is 6:59 AM EST on Dec 25.

The peak is essentially right before 12:00 UTC on Dec 25 — which is ~6:59 AM EST on Dec 25.

Why that moment is “best”:

• The last inhabited time zone is UTC−11 (American Samoa) Wikipedia
• The earliest time zones include UTC+14 (Line Islands/Kiribati) Time and Date
• At 11:59 UTC on Dec 25: - UTC−11 is 12:59 AM Dec 25 → already on Christmas Day (so no big population is still on Dec 24). Time and Date - UTC+12 is 11:59 PM Dec 25 → still on Christmas Day. Wikipedia - Only UTC+13 and UTC+14 have rolled into Dec 26 already — and those time zones contain a tiny share of the world’s population relative to Asia/Europe/Africa/Americas. Time and Date

So ~6:59 AM EST on Dec 25 is the point where the highest percentage of the world’s population is on Dec 25 (with only a small slice in the far-forward Pacific already on Dec 26).