<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi, Jim --<div>Does the original descriptor file have a 365_day_calendar? </div><div>--Jennifer</div><div><br><div><div>On Oct 7, 2013, at 2:36 PM, James T. Potemra wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">
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Hi all:<br>
<br>
I'm wondering if anyone knows how GDS derives a date-time value from
a GrADS style binary file? For example, a contributed data set
could have a descriptor file with a TDEF defining a start-date of
Jan 1, 2013 and increment of 1dy. If this file were served via GDS,
the OPeNDAP date-time becomes "days-since-1-1-1". In experimenting
with some GDS-served files, it seems that this conversion is off by
two days.<br>
<br>
Here's an example. The following is daily measurements from
QUIKSCAT:<br>
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<a class="moz-txt-link-freetext" href="http://apdrc.soest.hawaii.edu/dods/public_data/satellite_product/QSCAT/qscat_daily">http://apdrc.soest.hawaii.edu:80/dods/public_data/satellite_product/QSCAT/qscat_daily</a><br>
<br>
The data descriptor file has the following:<br>
TDEF 3776 linear 20JUL1999 1DY<br>
<br>
and the DDS page seems to have the correct values for time:<br>
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<table>
<tbody>
<tr>
<td align="right" valign="top"><b>time</b>:</td>
<td align="left" valign="top">Array of 64 bit Reals [time =
0..3775]
<br>
grads_dim: "t"
<br>
grads_mapping: "linear"
<br>
grads_size: "3776"
<br>
grads_min: "00z20jul1999"
<br>
grads_step: "1dy"
<br>
units: "days since 1-1-1 00:00:0.0"
<br>
long_name: "time"
<br>
minimum: "00z20jul1999"
<br>
maximum: "00z19nov2009"
<br>
resolution: 1.0
</td>
</tr>
</tbody>
</table>
<br>
However, the OPeNDAP supplied first time-step is 729956 (obtained
either through python call or ncdump). I think that this
corresponds to July 22, 1999 rather than the actual July 20, 1999 as
defined in the descriptor file.<br>
<br>
Can anyone comment on what's going on here? I found the same
behavior with two other daily files, same apparent 2-day off-set.
Thanks,<br>
<br>
Jim<br>
</div>
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<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>--</div><div>Jennifer M. Adams<br>Center for Ocean-Land-Atmosphere Studies (COLA)<br>111 Research Hall, Mail Stop 2B3<br>George Mason University<br>4400 University Drive<br>Fairfax, VA 22030 <br><br></div><div><br class="khtml-block-placeholder"></div><br class="Apple-interchange-newline"></span></span></div></span></span><br class="Apple-interchange-newline">
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