[NARCCAP-discuss] time discrepancy

[Shane Brennan]

OK, thanks, Seth. Is the same calendar used for all models? Is there
documentation on the timesteps used?

Shane

On Sat, Aug 25, 2012 at 11:25 AM, Seth McGinnis <mcginnis at ucar.edu> wrote:
> Hi Shane,
>
> It's the calendar.  CCSM uses a 365-day or "noleap" calendar, in which every
> year has 365 days and there are no leap years ever.  The date calculation
> functions in Excel use the standard Gregorian calendar, which does have leap
> years.
>
> If you count up the leap days between the base time (1968/01/01) and the start
> of your file (1996/01/01), there are seven of them, which is the difference
> between your expected start date and the start date you're seeing in the Excel
> calculations.  (And then there's another one in 1996, so the discrepancy for
> the end dates is 8 days.)
>
> Cheers,
>
> --Seth
>
> On Fri, 24 Aug 2012 11:13:44 -0400
>  Shane Brennan <sbren006 at odu.edu> wrote:
>>Hi,
>>
>>I am writing a C# program to parse and manipulate NARCCAP data. I
>>wanted to verify the missing data values to make sure I was handling
>>them correctly so I checked out:
>>
>>http://www.narccap.ucar.edu/data/missing/CRCM_ccsm-current_table3_missing.txt
>>
>>to find where I could look for missing values. In the URL above, it
>>states that evps in the file evps_CRCM_ccsm_1996010103.nc has missing
>>values for 1999-12-01 03:00 through 2000-01-01 00:00.
>>
>>I would expect the time series for the entire file to run from
>>1996-01-01 03:00 to 2000-01-01 00:00. However, when I parse this file
>>with my program and then use excel to calculate the times from
>>1/1/1968 (the start date returned from ncdump for this file), I get a
>>time series that runs from 12/25/1995 03:00 to 12/24/1999 00:00. In
>>this file, my missing values run from 11/23/1999 03:00 to 12/24/1999
>>00:00.
>>
>>Naturally, I became concerned that I had a bug in my program. However,
>>when I use nc2text.exe using the instructions detailed in the ASCII
>>HowTo, I get the same results.
>>
>>In Excel I calculate the offset date by entering 1/1/1968 into a cell,
>>and calculating a new field as that cell value added to each time
>>value (for example, if the cell for 1/1/1968 is G1, then my formula
>>for the first cell is "=$G$1 + a1". I then copy this formula all the
>>way down).
>>
>>Does anyone know what is going on? Perhaps there is some issue with
>>leap years or DST?
>>
>>Shane
>>_______________________________________________
>>narccap-discuss mailing list
>>narccap-discuss at mailman.ucar.edu
>>http://mailman.ucar.edu/mailman/listinfo/narccap-discuss
>
> _______________________________________________
> narccap-discuss mailing list
> narccap-discuss at mailman.ucar.edu
> http://mailman.ucar.edu/mailman/listinfo/narccap-discuss
>
>
> --
> BEGIN-ANTISPAM-VOTING-LINKS
> ------------------------------------------------------
>
> Teach CanIt if this mail (ID 696947847) is spam:
> Spam:        https://www.spamtrap.odu.edu/b.php?i=696947847&m=6c433a3fa195&t=20120825&c=s
> Not spam:    https://www.spamtrap.odu.edu/b.php?i=696947847&m=6c433a3fa195&t=20120825&c=n
> Forget vote: https://www.spamtrap.odu.edu/b.php?i=696947847&m=6c433a3fa195&t=20120825&c=f
> ------------------------------------------------------
> END-ANTISPAM-VOTING-LINKS
>