calcurse: notify whole-day events every morning

The calcurse daemon only alerts timed appointments, so birthdays went unnoticed. A daily 09:00 timer, started from xmonad and persistent across suspend, sends today's events through notify-send.

.config/systemd/user/calcurse-today.timer

@@ -0,0 +1,6 @@
+[Unit]
+Description=Notify today's calcurse events every morning
+
+[Timer]
+OnCalendar=*-*-* 09:00
+Persistent=true