<html><head></head><body>Hi Simon - <br>NOAA decided not to include day of week in any of their gribs starting 1/1/2021. I didn't get the memo either nor do I understand the rationale.<br><br>Good news is William LaForce figured out some exceptionally elegant code to determine day of week using year, month and day date.<br><br>Look in the archives or I'll attach the main logic below.<br><br>Hope that helps.<br>Mark<br><br>- - -<br>From post on 12/22/20:<br><br>After breaking down the month into a numerical value as you did, use that along with the day and current year into a function as such:<br><br><br>if (month < 3)<br> month = month + 12<br> year = year -1<br>endif<br><br>dow = math_mod(day + math_int((13*(month+1))/5) + year + math_int(year/4) - math_int(year/100) + math_int(year/400),7)<br><br><br>from here, the value 0 is Saturday, 1 is Sunday...6 is Friday_____________________________________________<br>William (L.B.) LaForce IV<br>Meteorologist<br><br><br><br><div class="gmail_quote">On January 2, 2021 2:38:58 AM PST, Simon Keeling <simon@weatherweb.net> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail">Hi all,<br><br>Since the turn of the year (2021), when using grib (such as GFS), the days of the week have been showing as ??? When using fday=(subwrd,3)<br><br>No changes have been made to scripts.<br><br>Wondered if anyone could suggest why this might be?<br><br>With thanks,<br>Simon Kerling<br><br></pre></blockquote></div><br>-- <br>Thanks <br>Mark Sponsler</body></html>