save the output to multiple files in crontab

There is a script scheduled in crontab.

0 2 * * * /usr/local/bin/backup.sh >> /root/output_all.txt

I want to save the output into multiple files like output_all.txt and output_date.txt at the same time. I know there is

command to save the output to the multiple files.
But

can be used only when tty exists? Is there any other solution?