BASH has its built-in variant of time. If you do a man time you will find that a lot of those option listed there won't work with time command. The man page warns BASH users that they may use explicit path to time.
The explicit path is /usr/bin/time on Ubuntu, but you can find it out with $ which time.
With the proper path, you can use the -f or --format option and a lot of formatting parameters that will nicely format your result which you can store to a variable as well.
STUFF_HERE=`/usr/bin/time -f %E sleep 1
2>&1`