DST March 9S

Oh No, Not Daylight Saving Time Again

This map shows the sky facing south at 8 p.m. Saturday night March 12. Diagram: Bob King, source: Stellarium
This map shows the sky facing south at 8 p.m. local standard time Saturday night March 12. Don’t forget to advance your clocks an hour that night. Diagram: Bob King, source: Stellarium

Watch out! Here it comes. Daylight Saving Time returns this Sunday at 2 a.m. An exercise in delayed gratification, “springing forward” means losing an hour of morning sleep we won’t reclaim until Sunday, Nov. 6. That’s not all – the stars take a big step back. You might you’ll think get that hour back on Sunday night by going to bed an hour early. Maybe some do. For whatever reason, I still go to bed at the same time.

This map shows the sky facing east at 8 p.m. local time on Saturday, March 12. Diagram: Bob King, source: Stellarium
This map shows the sky facing east at 8 p.m. local standar time on Saturday, March 12. Diagram: Bob King, source: Stellarium

Moving forward an hour advances the time of sunset from around 6 p.m. to a sudden 7 p.m. with nightfall starting around 8:30.  It also advances the sunrise hour from about 6:30 a.m. to 7:30. Darker mornings are appreciated for sleep’s sake, though I know a lot of people who prefer to run or walk their pets in more light rather than less. Most see extra light in the evening as a benefit; no longer does dinner time lead directly to nighttime. There’s time to get out, perform a task or take a stroll.

This map shows the sky one night later at the same time. Notice how the constellation have shifted back to the left. Even though the clock time reads the same, you're really out looking one hour earlier. Diagram: Bob King, source: Stellarium
This map shows the sky one night later on March 13 at 8 p.m. local daylight saving time. Notice how the constellation have shifted back to the left. Even though the clock time reads the same, you’re really looking at the sky one hour earlier. Diagram: Bob King, source: Stellarium

But the arrival of Daylight Time (DST)  makes for a striking change in the night sky. Later sunsets act as a “brake” on the spring stars. If you go out Saturday evening at 8 p.m. and face south, Orion will lie to the right of the meridian, the north-south line that begins at the due south point on the southern horizon, passes through the overhead point and end at the due north point on the northern horizon. When a star or planet crosses the meridian in the southern sky, it’s at its highest point above the horizon.

This map shows the eastern sky on Sunday night at 8 p.m. Jupiter is quite a bit lower at that time compared to the night before. Diagram: Bob King, source: Stellarium
This map shows the eastern sky on Sunday night at 8 p.m. local daylight saving time Jupiter is quite a bit lower at that time compared to the night before. Diagram: Bob King, source: Stellarium

Sirius, easily found by shooting a line through Orion’s Belt downward, is very close to the meridian at that time. In the eastern sky, brilliant Jupiter is plainly visible. But the very next night at that same 8 p.m. time we see a different scene. First, it’s still twilight out and second, Sirius is an hour from its due south point. Look east and Jupiter is a full fist lower in the east. That’s because the time is really 7 p.m. not 8 p.m., an hour earlier. DST artifice makes the winter stars linger longer while “holding back” the spring stars clamoring in the eastern sky.

1918 post card that citizens could mail to their congressman to show support for the daylight saving time law, which was enacted on March 19, 1918 in the U.S. Click to read the history of DST. Credit: Library of Congress
1918 post card that citizens could mail to their congressman to show support for the daylight saving time law, which was enacted on March 19, 1918 in the U.S. Click to read the history of DST. Credit: Library of Congress

That may not be a bad thing, but once I get used to seeing Jupiter up high, I don’t like having to start all over again and wait that extra hour for the extra altitude. Or maybe I’m just getting cranky? What I need is some extra sleep. Darn. Looks like I won’t be getting that either!

Night sky cover*Special note: The book I’ve been working about how to see and enjoy the night sky without any special equipment but your eyes is now available for pre-order on Amazon and at Barnes and Noble. It’s titled Night Sky with the Naked Eye and will be published by Macmillan on September 20th. If you’ve noticed my blog disappear for a day or two, it’s because I’ve been busy on the project since last fall. I appreciate your patience, and I think you’ll enjoy the book.

2 Responses

  1. Troy

    Congrats on the book. I’m sure when you open the spigots it just flows out of you. In the description it says it covers the Southern hemisphere. I’m just curious have you been able to get some practical experience down under? I’d like to spend a year in Australia someday, but don’t think it’ll happen. Of course you never know.

    1. astrobob

      Thank you Troy. Good point about the southern hemisphere – unfortunately that’s incorrect. It covers only the northern. I e-mailed the published and they’ve changed it but apparently it will take a couple weeks for the change to take effect. I’ve been to the southern hemisphere several times but only once where I could study the sky.

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