I'm using the spreadsheet capabilities of org for the first time (very
cool!) to plan an upcoming trip.  I'd like to create a column formula to
automatically calculate the dates/day of week but I'm a bit stumped.  I
don't see a way for the formula to know which row it is currently
processing.  I'm also coming up short trying to find any elisp to go from
day of year -> formatted date string.  Any suggestions?