# How many hours in a day ?

I am wondering how many hours a day could potentially be. Going by calendar time, if I were to leave NY at 0am fly to LA and arrive at 12 noon I would have gained two hours time on ant specific date. Using an airplane to travel how many hours could I extend a calendar day?

If you really want to be picky, a mean solar day is 24 hrs, but not a true earth rotation relative to the sun. In the northern winter, a day has less than 24 hrs since the earth is moving faster in its orbit. Hence, the sun returns to culiminate on the observer’s meridian in less than 24 hrs. The reverse it true in the northern summer. This is known as the equation of time often expressed in tabular form and applied as an adjustment to sundials…like one could read a sundial all that accurately, right? (In short, the combined motions of the earth play into our measurement of time based on the sun’s return to the observer’s meridian.)

It’s nit-picky, but just some food for thought. And, it might “buy” you a little time!

• Jinx

My longest days have been 40 hours – starting on the East coast of Australia in summer, and arriving in Ohio in winter. You could increase the day to about 46 hours by flying from New Zealand to Hawaii.

(You do have a night in the middle, but since you cross the International Date Line, the sun rises again on the same day as you started).

Thank you. I knew that there had to be a definite amount of time, :smack:

Depending on your definition of “day”, a day could last forever.

At a latitude in middle Canada a westbound jetliner can go faster than the sun sets. If we found 3 airports around the world at suitable intervals, you could fly forever on the same day. Here’s how:

Take off from one airport (#1) at say, mid-morning, go west for about 8 hours & land at the next airport (#2). Based on the sun angle, it’s early morning at that airport. Spend an hour refueling & doing maintenance, then take off again at mid morning and continue west for eight more hours to airport 3.

Again you’ll be going faster than the sun and again you’ll be landing in the early morning at airport #3. Spend another hour refueling, dumping lavs & reprovisioning food, then take off at mid morning for airport #1. 8 hours later you arrive back at airport #1 in the early morning.

24 hours have elapsed & yoou’ve flown around the world, but the local time where you were has never been anything but something between 8am & 10am.

You can do this until you die of old age or run out of money.

If you did that for a whole week, would that be 1 day? The sun never set where you were and the local time was always roughly the same; 9-ish AM. Sounds like a week-long day to me.

Yes you could follow the sun but my question was based on a calander day.

I’m not sure I’m understanding your example. First, it doesn’t take 15 hours to get from NY to LA, so this route wastes a lot of time when your flyer could have been progressing across time zones. Second, LA is 3 hours behind NY, not 2. Am I missing something?

Isn’t the answer just shy of 48 hours? Hire a boat, and sit next to the international date line starting at midnight on January 1. At exactly 24hours later, cross the date line. It’s now midnight again, but still January 1. You get a second 24 hours of January 1.

Back in 1999, I was rather surprised that I didn’t see advertising for cruise ships doing exactly that. They could have offered back to back New Year’s Eve 1999-2000 parties.

This was keeping me awake last night for some reason, and I get the more or less the same answer that ToC does (47 hours, 1 second exactly).

Assumptions: None of the “weird” (non-hour) time zones abut the international date line, and that you’ve got fast chartered planes waiting.

You sit next to the IDL, and wait for it to become midnight in your time zone. There are 24 hour-separated time zones, and you’re in one of them. 23 hours later, the last time zone switches to midnight of the same day you’re in, and has exactly 24 hours left in it’s day. If you wait for a day with a leap second (they come along every few years), you can get an extra second. Ignoring the leap second, you get exactly 47 hours, and a pretty wide swath of land/sea at each end to start/end in. You’ve either got to follow the sun or hop the date line in the last/first hour of the day.

Ya Know, I tried this as a ‘bar bet’ one time, convinced that that a ‘day’ lasted 48 hours, but no matter how much I scribbled out time zone sections and waved cocktail napkins, I couldn’t convince my friend I was right.