To generate a back up of a crontab file is actually pretty simple, making use of the built in -l switch that comes with the command:

sudo crontab -l > ~/path/to/your/backup/file

See what we did there? The -l switch spits out the crontab file’s contents and we simply pipe that into a file. Easy peasy. Note that sudo crontab and crontab are two different files, meaning you might want to backup both if you make use of the two different cron job files…