Crontab backup

I have three users on my server
a) root
b) oracle
c) download

i want to take backup of cron for everyuser everyday. Is there any way to schedule this process.

CRONTAB(1) FreeBSD General Commands Manual CRONTAB(1)

NAME
crontab -- maintain crontab files for individual users (V3)

SYNOPSIS
crontab [-u user] file
crontab [-u user] { -l | -r | -e }

... Did you try crontab(1)?

Have you thought of scheduling a cron job for this?

you can edit crontab file >(crontab -e) command...but if you want to take oracle backup you must stop oracle after start backup...are your backup ufsdump backup???

I think that the OP wants to backup the crontab files for every user every day. This would be as simple as doing a 'cp -p' of the crontab files. Use the following script:

today=$(date +%Y%m%d)
mkdir /some_backup_dir/$today
cp -p /var/spool/cron/crontabs/* /some_backup_dir/$today

Maintain the following cron entry in root's crontab:

00 01 * * * /full_path_of_script/whatever_you_call_this_script