Results 1 to 9 of 9

Thread: Gap in data due to daylight savings?

  1. #1
    Join Date
    Nov 2006
    Location
    New Hampton, NH
    Posts
    832
    Thanks
    2
    Thanked 15 Times in 8 Posts

    Default Gap in data due to daylight savings?

    When you're logging weather data, how do you account for daylight savings time? Is there just a 1 hour gap in the logs (based on time?)

    Kirk

  2. #2
    Join Date
    Jul 2007
    Location
    Epping, NH
    Posts
    658
    Thanks
    8
    Thanked 58 Times in 25 Posts

    Default

    That's a simple one...the OBS stays on standard time year round. No time change.

    In fact, there are three clocks that the observers get used too. Standard (the time that the observatory observes), Daylight (the time the rest of the summit observes), and ZULU (Greenwich, the time that the rest of the meteorological world observes). You get used to it...

    The observers slide shifts slightly. In the comments today, Mike F talks of now waking up at 4AM to do the work that usually was done at 5AM. This is to make sure that the radio shows in the morning are all done by the same people on the same routine, but the clocks dont change.
    "I've learned that everyone wants to live on top of the mountain, but that all the happiness and growth occurs while you're climbing it."
    ~Andy Rooney

    Follow my photography on Facebook:http://www.facebook.com/pages/Jim-Sa...y/156147782386

  3. #3
    Join Date
    Oct 2006
    Location
    Connecticut
    Posts
    2,680
    Thanks
    7
    Thanked 33 Times in 29 Posts

    Default

    If you think about it, the Obs wouldn't miss any data if they set their clocks ahead. The observer would go out at 12:55am and get the data. They move the clocks at 1:00am and the next observation is at 2:55am. You didn't miss an ob, you just changed the time.

    The reason they stay on EST or GMT is not about missing data, its about consistency in the records. Universal time is a constant, DST is arbitrary.
    Bill
    Next up: Vermont City Marathon: May, 2011
    EasternLight

  4. #4
    Join Date
    Nov 2007
    Location
    New Hampshire
    Posts
    163
    Thanks
    4
    Thanked 35 Times in 25 Posts

    Default

    Being a software engineer, and having written much software that records time series data, the rule is always to record UTC and the value. When graphing, displaying or reporting, you can easily convert the UTC record from the database into a local time which includes the DST adjustment as necessary. So, today's 24-hour window includes 23 hours. When we "fall back" the 24-hour window would include 25 hours.

    Tim

  5. #5
    Join Date
    May 2006
    Posts
    542
    Thanks
    0
    Thanked 2 Times in 1 Post

    Default

    Universal time is arbitrary, DST is inconsistent.

    I'm splitting hairs, yes, but I think arbitrariness is okay for science. Inconsistency is not. Examples of arbitrariness: the length of a meter, the number of seconds in a minute, the diameter of a precip can. These measures produce good science when applied consistently.

    Taking 23 observations in one day and 25 another day is just wacky from a scientific perspective.

    Quote Originally Posted by Bill O
    Universal time is a constant, DST is arbitrary.

  6. #6
    Join Date
    May 2006
    Posts
    542
    Thanks
    0
    Thanked 2 Times in 1 Post

    Default

    Unix time is the only way to go. Why would you say "It's Friday, March 21st" when you could just say "1206152257". Of course, if you'd rather do everything the hard way, there are X's of M's of ways to represent numbers.

    Quote Originally Posted by bikehikeskifish
    Being a software engineer, and having written much software that records time series data, the rule is always to record UTC and the value. When graphing, displaying or reporting, you can easily convert the UTC record from the database into a local time which includes the DST adjustment as necessary. So, today's 24-hour window includes 23 hours. When we "fall back" the 24-hour window would include 25 hours.

    Tim

  7. #7
    Join Date
    Dec 2007
    Location
    Rhode Island
    Posts
    1,994
    Thanks
    60
    Thanked 243 Times in 126 Posts

    Default

    Quote Originally Posted by Mike D
    Unix time is the only way to go. Why would you say "It's Friday, March 21st" when you could just say "1206152257". Of course, if you'd rather do everything the hard way, there are X's of M's of ways to represent numbers.
    It's definitely the only way to go - as long as you can deal with the fact that the big bang happened in 1970
    Mark

    Keep close to Nature's heart...
    and break clear away, once in awhile,
    and climb a mountain or spend a week in the woods.
    Wash your spirit clean. - John Muir


    Hiking photos: http://picasaweb.google.com/mtruman42
    Hiking Blog: http://theramblingsblog.blogspot.com/
    Seek the 2011 Peak page: Mark Truman's Pledge Page

  8. #8
    Join Date
    Sep 2006
    Location
    Maine
    Posts
    6,247
    Thanks
    112
    Thanked 398 Times in 250 Posts

    Default

    Quote Originally Posted by mtruman
    It's definitely the only way to go - as long as you can deal with the fact that the big bang happened in 1970
    I had heard the big bang was coming this summer when Steve is up on the summit cooking.
    Brad (a 6288 club member)
    http://bradstreet.zenfolio.com Personal Photo sales site
    http://public.fotki.com/bradbradstreet Personal photo web site
    http://public.fotki.com/MWO/saved/2012/ MWO image & video archive site 2006-2012

  9. #9
    Join Date
    Oct 2006
    Location
    PA
    Posts
    2,145
    Thanks
    541
    Thanked 121 Times in 73 Posts

    Default

    Quote Originally Posted by Brad
    I had heard the big bang was coming this summer when Steve is up on the summit cooking.

    it better not go bang until after we summit
    i am a Summit Club member
    http://public.fotki.com/hvachawk/new pictures and videos

    If your not a OBS member yet then what are you waiting for

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •