“Wednesday is canceled.”
No, really! Those of us on ship won’t see Wednesday this week. We’ll go to bed tonight (Tuesday) and will wake up Thursday morning.
It’s confusing for those who have calls scheduled for tomorrow. Er, Wednesday. For them, the call will be on Thursday. Clear as mud?
Our current time zone on the ship is UTC–10, same as Hawaii. For work reasons, I keep my computer on Colorado time, since I lived there for so long and my internal deadlines are based on Colorado times. As we sleep tonight, ship time will “suddenly” change to UTC+14.
In other words, the clock will jump forward by 24 hours. Wednesday won’t exist. We really will go to bed Tuesday night (tonight), and wake up Thursday morning.
Of course, it’s all just a matter of semantics, but we need to “catch up” to what the time is in our next destination. As I’m writing this at 3:33 p.m. Tuesday, Ship Time, which is 7:33 p.m. Colorado Time, while in Tokyo it’s 10:33 a.m. — Wednesday morning.
Logically it’s easy, but some Residents are having trouble getting their minds around it all. It feels goofy: an emotional reaction.
International Date Line
It all has to do with the International Date Line, “the line extending between the South and North Poles that is the boundary between one calendar day and the next. It passes through the Pacific Ocean, roughly following the 180.0° line of longitude and deviating to pass around some territories and island groups. Crossing the date line eastbound decreases the date by one day, while crossing the date line westbound increases the date.
“The line is a cartographic convention and is not defined by international law. This has made it difficult for cartographers to agree on its precise course and has allowed countries through whose waters it passes to move it at times for their convenience.” —Wikipedia.
And we cross it in the next several hours.
UTC-0 — hour 0 of “Coordinated Universal Time” — is the time in Greenwich, England. When I was a kid, it was called Greenwich Mean Time. That’s where, simply by definition, the 0° line of longitude passes through, and where the day starts. As time zones march across the world, there are (theoretically) 24 time zones.
I say theoretically because there are exceptions and oddities that I won’t even try to get into here. Politically, the time zone borders often aren’t straight lines, but bend around state, country, or island borders:
Related: What time is it on the ship? Whatever the captain says it is.
P.S.: Yes, we are monitoring the Tsunami generated by today’s 8.7 earthquake off Russia’s Kamchatka Peninsula. Being at sea, we are completely safe from it, even though it is threatening Japan, Hawaii, and the west coast of North America.
Originally Published July 29, 2025 — Last Updated July 29, 2025- About the Author
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So glad to hear that the Tsunami won’t affect you while at sea. I hope it doesn’t affect any of your Japanese destinations.
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We hope not too! -rc
One of my favourite stories that may or may not be true (I have seen it marked as not true online, but I have seen David Lee Roth claim it’s true in interviews).
Van Halen singer David Lee Roth did not have a 30th birthday. He was on a plane to Australia, and the day that was skipped would have been his 30th birthday.
I felt bad for him at the time, but then realised that David Lee Roth has more fun every single day than most people have on their 30th birthday.
Living In Rarotonga for many years handling the Dateline oddities is just second nature. But it does confuse even the most experienced travelers. Recently I left Rarotonga, Cook Islands at 2300 (11PM) (UTC-10) on Friday the 18th of July. I arrived in Auckland New Zealand after a 4hr flight at 1AM on Sunday the 20th of July!!! (UTC+12). Calendar-wise my flight was about 26 hours.
I have frequently had 2 birthdays, Xmas’s, etc. going the other way. Just double check your dates if travelling trans-Pacific.
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It’s easy being on a ship: we just sit tight and go along for the ride. 🙂 -rc
My experience, this did happen 50 or so years ago so details might be fuzzy.
We left Guam where I had been stationed and flew to Hawaii as a stop on our way to New York. When we arrived in Hawaii, if I remember correctly, the time was before or about the same as when we left Guam.
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You and the next comment I’m about to approve! -rc
I remember coming home from the first time I visited Australia. We arrived home in Southern California an hour before left Australia! Now that’s a fast flight!
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I’m approving a few of these examples to illustrate why it’s a bit hard to wrap one’s head around going over the IDL. -rc
My experience of going back in time was aboard a Navy ship (USS Damato DD-871) returning from a tour in the Gulf of Tonkin (Vietnam War). While we were west of the dateline, and steaming east, we passed from 1967 into 1968. Then we crossed the dateline and went back to 1967. A while later we again entered 1968. With two New Years Days, I thought we might get two holidays, but the captain declared one of them to be a work day. Oh well.
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Nice try. -rc