[NARCCAP-discuss] time discrepancy

[Shane Brennan]

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