# Earth in space and time **URL:** \ **Category:** Factual Questions\ **Created:** [March 20, 2013, 8:04pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485 "2013-03-20T20:04:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![mbloom1](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@mbloom1](https://boards.straightdope.com/u/mbloom1)\ **Post date:** [March 20, 2013, 8:04pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/1 "2013-03-20T20:04:51Z")
The day before daylight savings time is implemented, upon waking up, one sees a brilliantly lit morning, weather permitting. Twenty-four hours later, at that same moment of the morning, it is pitch black outside. All due to an interesting desire to ‘save daylight time’. My question: How far, theoretically, in days, has the earth been ‘pushed back’ in its orbit to result in this great loss of light upon waking? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 20, 2013, 8:06pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/2 "2013-03-20T20:06:55Z")
I think you need to clarify what you mean. Of course the Earth has not been “pushed back” in any way and there has been no loss of light. Your question can be interpreted in various ways. ---
**Author:** ![RedSwinglineOne](https://avatars.discourse-cdn.com/v4/letter/r/a9adbd/32.png) [@RedSwinglineOne](https://boards.straightdope.com/u/RedSwinglineOne)\ **Post date:** [March 20, 2013, 8:15pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/3 "2013-03-20T20:15:23Z")
> [@mbloom1](#): > > . Twenty-four hours later, at that same moment of the morning, it is pitch black outside. ? Twenty-three hours later. ---
**Author:** ![QuickSilver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quicksilver/32/7832_2.png) [@QuickSilver](https://boards.straightdope.com/u/QuickSilver)\ **Post date:** [March 20, 2013, 8:18pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/4 "2013-03-20T20:18:06Z")
Depends on your [latitude.](http://en.wikipedia.org/wiki/Day_length) For sake of rough calculation, something in the northern hemesphere at 45 degrees latitude, an hour is about 30 days pushed back (or forward), as the case may be. ---
**Author:** ![cjepson](https://avatars.discourse-cdn.com/v4/letter/c/a9adbd/32.png) [@cjepson](https://boards.straightdope.com/u/cjepson)\ **Post date:** [March 20, 2013, 8:28pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/5 "2013-03-20T20:28:47Z")
If I understand the intent of your question correctly, the institution of Daylight Savings Time does not push our home planet back in its orbit; it simply stops its rotation for an hour. Much easier. ---
**Author:** ![Noone\_Special](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/noone_special/32/2863_2.png) [@Noone\_Special](https://boards.straightdope.com/u/Noone_Special)\ **Post date:** [March 20, 2013, 8:39pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/6 "2013-03-20T20:39:45Z")
I think **QuickSilver** ’s interpertation of the question is the correct one – i.e., “if DST starts on March 16, then on the 17th the sunrise is (almost) an hour later than it was on the 16th. What is the date in (Jan? Feb?) on which the sun rose at the same time as it did on March 17?” In other words “How many day have we gone back” = “how many days ago was the sunrise at the same time as today.” As notes, this will depend strongly on altitude. The best way is probably to check your location’s coordinates (lat and long) and then consult an almanac that will give you Sunrise times at your location. In truly Northern (or Southern, in the Southern hemisphere) locations, the “pushback” could be as little as a few days. near the equator, the question is effectively meaningless (as is DST…) There will still be a lot of variance in temperate climates too. Off the cuff, where I am (roughly 30N) there is about 4 hours difference in daylight between Winter and Summer solstices, so 1 hour is equivalent to about a month and a half. This will be significantly different at 45N. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [March 20, 2013, 8:40pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/7 "2013-03-20T20:40:33Z")
Not to mention, even if we were to accept the silly notion that Daylight Savings has a physical effect on the planet, any effect in the springtime would be exactly offset by the reverse effect in the autumn when Daylight Savings ends. ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [March 20, 2013, 8:55pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/8 "2013-03-20T20:55:10Z")
At my latitude, on the first day of DST sunrise was 7:12 am, same as it was on Feb 4 under Standard Time. So little more than a month. Of course, your latitude may vary. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [March 20, 2013, 8:58pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/9 "2013-03-20T20:58:29Z")
But remember, sunset gets later, too, so the planet has also been pushed forwards! For London: The first day of BST is Mar 31 this year. Sunrise is at 6:38 BST on that day. > **[Sun & moon times today, London, England, United Kingdom](https://www.timeanddate.com/astronomy/uk/london)** > > Time for sunrise, sunset, moonrise, and moonset in London – England – United Kingdom. Dawn and dusk (twilight) times and Sun and Moon position. Takes into account Daylight Saving Time (DST). The closest times to that are 6:39 and 6:37 GMT on March 4 and 5 respectively. Similarly, sunset is at 19:32 BST on March 31, and at 19:32 GMT (i.e. 20:32 BST) on May 6. So implementing BST pushes the planet backwards 26 and a half days in the morning, and forwards 36 days in the evening. 🙂 ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [March 20, 2013, 9:16pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/10 "2013-03-20T21:16:47Z")
Besides, the sun is now higher in the sky than it was a month ago. The correct way to look at the question is how far back the Earth has rotated and the answer is 15deg. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [March 20, 2013, 10:29pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/11 "2013-03-20T22:29:16Z")
> [@cjepson](#): > > If I understand the intent of your question correctly, the institution of Daylight Savings Time does not push our home planet back in its orbit; it simply stops its rotation for an hour. Much easier. Or, more correctly, we have merely transformed the reference coordinate frame for time system by -pi/12 radians (-15°), which is easier still, because then we don’t have to explain the failure of otherwise universal conservation of angular momentum for almost eight months. The epoch is not adjusted with respect to celestial coordinated because that would result in a disconnect between the true orientation of the Earth’s axis with respect to the ecliptic coordinate system and the orientation predicted by the ‘adjusted’ date, which would also give incorrect interval of the solar day and maximum declination (altitude at solar noon) of the Sun. Stranger ---
**Author:** ![Fubaya](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@Fubaya](https://boards.straightdope.com/u/Fubaya)\ **Post date:** [March 21, 2013, 12:06am UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/12 "2013-03-21T00:06:09Z")
Some places don’t even observe daylight savings time. For me, the first day of DST had a sunrise of 7:53 AM and looking backward, there isn’t another 7:53 until Oct 26, 2012. That was before setting the clocks back in the fall. But, if it stretches over both clock changes, it kind of cancels out doesn’t it? The closest it came otherwise was 7:47 on Jan 10. I’d say that counts. It’s only 6 minutes, it’s not like it’s a difference of night and day… ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [March 21, 2013, 3:35am UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/13 "2013-03-21T03:35:01Z")
I thought the heat from the extra hours of sunlight that DST gives us in the evenings is what pushed the Earth back in its orbit. ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [March 21, 2013, 4:53am UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/14 "2013-03-21T04:53:40Z")
Okay, I can’t tell who’s being serious and who’s joking so at the risk of offending someone but for the sake of clarity: Daylight Savings Time is \*\*NOT _in any way, shape or form_ a **‘natural’** phenomenon. It is not like the first day of Spring (the vernal equinox) or the first day of Summer (the solstice). It is a **completely artificial invention** that exists (or in some areas doesn’t) strictly for the convenience of us predominantly daylight-dwelling humans. Daylight is neither created nor eliminated, but merely shifted (or ‘saved’) via relabeling of the clock hours for use at the end of the day (early evening) instead of the beginning (early morning). The Earth is not at any special point in its orbit around the Sun nor in its tilt toward it nor in its own rotation etc. We are merely sacrificing one hour of one day on a Saturday night/Sunday morning in the Spring in order to push the time hour number ahead 1 for most all of Spring, Summer & Fall when it’s warm out so that we can make better use of this predominantly warm weather in the early evening instead of it being ‘wasted’ in the very early morning. We do the opposite in the Fall/Winter because: A) It’s no longer warm in the daytime much at all, and B) The daytime has become shorter than the night so we now need the extra daylight more in the (now late) morning instead of the (now early) afternoon. It is also \*\*NOT \*\*some ‘quirk’ of our calendar that requires bi-annual adjustment, like during the one-time switch from the Julian to the Gregorian systems where ten calendar days were skipped in 1582 CE to fix a cumulative error from the leap year days. It was, I believe, invented in America in the early 20[sup]th[/sup] century because the population had changed from a predominately agrarian one to an urban one (i.e. from farms to cities). ---
**Author:** ![spifflog](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@spifflog](https://boards.straightdope.com/u/spifflog)\ **Post date:** [March 21, 2013, 11:53am UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/15 "2013-03-21T11:53:05Z")
> [@Hail\_Ants](#): > > Okay, I can’t tell who’s being serious and who’s joking so at the risk of offending someone but for the sake of clarity: > > Daylight Savings Time is \*\*NOT _in any way, shape or form_ a **‘natural’** phenomenon. It is not like the first day of Spring (the vernal equinox) or the first day of Summer (the solstice). It is a **completely artificial invention** that exists (or in some areas doesn’t) strictly for the convenience of us predominantly daylight-dwelling humans. Daylight is neither created nor eliminated, but merely shifted (or ‘saved’) via relabeling of the clock hours for use at the end of the day (early evening) instead of the beginning (early morning). The Earth is not at any special point in its orbit around the Sun nor in its tilt toward it nor in its own rotation etc. No no. Your wrong. One of the reasons we have the space station is there is to push the earth around for DST. It’s harder to pull it back, that’s why they do that in the fall. It’s later in the year so thay have more time to fix that kinka stuf. Ignerance faught by but!! ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [March 21, 2013, 2:03pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/16 "2013-03-21T14:03:03Z")
> [@Hail\_Ants](#): > > It is not like the first day of Spring (the vernal equinox) or the first day of Summer (the solstice). Obviously the equinoxes and solstices are absolute and independent of our artificial timekeeping. But not everyone corresponds these dates with the first day of the seasons. There’s no reason why the first day of summer has to fall on the summer solstice, for example, and in many countries it doesn’t. ---
**Author:** ![cjepson](https://avatars.discourse-cdn.com/v4/letter/c/a9adbd/32.png) [@cjepson](https://boards.straightdope.com/u/cjepson)\ **Post date:** [March 21, 2013, 2:42pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/17 "2013-03-21T14:42:06Z")
> [@Stranger\_On\_A\_Train](#): > > Or, more correctly, we have merely transformed the reference coordinate frame for time system by -pi/12 radians (-15°), which is easier still, because then we don’t have to explain the failure of otherwise universal conservation of angular momentum for almost eight months. The epoch is not adjusted with respect to celestial coordinated because that would result in a disconnect between the true orientation of the Earth’s axis with respect to the ecliptic coordinate system and the orientation predicted by the ‘adjusted’ date, which would also give incorrect interval of the solar day and maximum declination (altitude at solar noon) of the Sun. Well, yeah, I was gonna say that… ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [March 21, 2013, 3:23pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/18 "2013-03-21T15:23:00Z")
This is soooooo typical of the threads where I wish the OP would come back and explain his question a bit better. But they almost never do. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [March 21, 2013, 3:30pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/19 "2013-03-21T15:30:14Z")
> [@Keeve](#): > > This is soooooo typical of the threads where I wish the OP would come back and explain his question a bit better. But they almost never do. The question posed in the o.p. seems pretty clear (“How far, theoretically, in days, has the earth been ‘pushed back’ in its orbit to result in this great loss of light upon waking?”) but it is based on a fundamental misapprehension that the transform is in terms of orbital epoch (i.e. the position at the Earth’s orbit about the Sun from some reference time) rather than a transform of the rotation frame of the Earth. Stranger ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [March 21, 2013, 3:36pm UTC](https://boards.straightdope.com/t/earth-in-space-and-time/653485/20 "2013-03-21T15:36:49Z")
> [@Stranger\_On\_A\_Train](#): > > The question posed in the o.p. seems pretty clear (“How far, theoretically, in days, has the earth been ‘pushed back’ in its orbit to result in this great loss of light upon waking?”) but it is based on a fundamental misapprehension that the transform is in terms of orbital epoch (i.e. the position at the Earth’s orbit about the Sun from some reference time) rather than a transform of the rotation frame of the Earth. > > Stranger You don’t think he is just trolling, pretending to think that the earth really did get pushed back? ( **mbloom1** , if your question was sincere, then I apologize for offending you just now. That’s why I wish you’d come back, and comment on these responses to your question.) [Next page](https://boards.straightdope.com/t/earth-in-space-and-time/653485.md?page=2)