Hi again,

notmuch search $(date +%s -d 2009-10-01)..$(date +%s -d 2009-10-02)

works wonders from the command line, but not from within Emacs:

M-x notmuch-search RET $(date +%s -d 2009-10-01)..$(date +%s -d 2009-10-02)

[Sat Aug 24 12:39:15 2013]
A Xapian exception occurred performing query: Unknown range operation
Query string was: $(date +%s -d 2009-10-01)..$(date +%s -d 2009-10-02)
command: notmuch search --format\=sexp --format-version\=1 --sort\=newest-first \$\(date\ \+\%s\ -d\ 2009-10-01\)..\$\(date\ \+\%s\ -d\ 2009-10-02\)
exit status: 1
stderr:
A Xapian exception occurred performing query: Unknown range operation
Query string was: $(date +%s -d 2009-10-01)..$(date +%s -d 2009-10-02)

I see --format=sexp -- does that mean we need to protect those
kinds of requests somehow?

Thanks for your help!

-- 
 Bastien