With this command you will see the calendar with first day monday.
echo `date "+%d %B %Y"` | cal | awk '{ getline; print " Mo Di Mi Do Fr Sa So"; getline; if (substr($0,1,2) == " 1") print " 1 "; do { prevline=$0; if (getline == 0) exit; print " " substr(prevline,4,17) " " substr($0,1,2) " "; } while (1) }' | awk -v cday=`date "+%d"` '{ fill=(int(cday)>9?"":" "); a=$0; sub(" "fill int(cday)" ","("fill int(cday)")",a); print a }'
Update: I have changed the command to:
cal | awk '{ getline; print " Mo Di Mi Do Fr Sa So"; getline; if (substr($0,1,2) == " 1") print " 1 "; do { prevline=$0; if (getline == 0) exit; print " " substr(prevline,4,17) " " substr($0,1,2) " "; } while (1) }' | awk -v cday=`date "+%d"` '{ fill=(int(cday)>9?"":" "); a=$0; sub(" "fill int(cday)" ","("fill int(cday)")",a); print a }'